


U. S. DEPARTMENT OE AGRICULTURE. 

BUREAU OF PLANT INDUSTRY— BULLETIN NO. 58. 



B. T. GALLOWAY, Cliirf „f Hurcau. 



T H K 



VITALITY AND (.RUMINATION OF SEEDS. 



J. W. T. DIJVEL, 

Assistant in the Seed Tvap.oratory. 



BOTANICAL INVESTIGATIONS AND EXPERIMENTS. 



] M M 







WASHINGTON: 

GOVERNMENT PRINTING OFFICE. 
1 9 4 . 



ttoW^hMll 




Glass. 
Book. 



/v 



U. S. DEPARTMENT OE ACRIClT/rURE. 

BUREAU OF PLANT INDUSTRY— BULLETIN NO. 58. 

]'.. T. (iAI,l,i)\V.\ V, clii,/ (if r.iirinn. 



the; 



6^^f 






VITALITY AND TERMINATION OF SEEDS. 



y ■ T 

J.MV/TM)IIVEL, 
Assistant in iiie Seed Lauoiiatoky, 



BOTANICAL INVESTIGATIONS AND EXPERIMENTS. 



Issued May 2S, 1004. 




WASHINGTON: 

GOVERNMENT PRINTING OFFICE. 






BUREAU OF PLANT INDTSTRY. 

Bkvkkly T. Galloway, Clilrf. 
J. E. Rockwell, Editor. 

BOTANICAL INVESTK^ATIONS AND EXPERIMENTS. 

SCIEM'IFK' S'lAVK. 

Frederick V. C'oville, Hdlmiist. 

(). F. Cook, Boldiiisl in, (1itirt/c of Investigations in Tmjncnl Ai/rirulturc. 

Rodney II. True, I'lii/sioloj/ist, Drug and Medicinal Plant Inrcstigations. 

Lyster II. Dewey, Botanist in Oiarge of Investigations of Filx-r Plants. 

Edgar Brown, Botanist in Charge of Seed Lahoratin'ii. 

Carl S. Scofield, Botanist in Charge of Grai)i (,'rade Inrrslig<(tio7is. 

G. N. Collins, Assistant Botanist, Tropical Agriculture. 

A. v. Crawford, Pharmacologist, Poisonous Plant InrcKtigations. 

William E. Safford, Assistant Curator, ■Tropic<d Agriculture. 

F. II. liiLLMAN, As.vMant Bota)iist, Seed Ilerlxvriuni. 

J. W. T. DuvEL, Assistant, Seed. Laboratory. 

W. W. Tracy, Jr., Assistant, Variety Trials. 

W. F. Wmnr, Assistant, deograpliic Botany. 

W . O. RiciiTMANN, Pharmacognostical E.rpert. 

Alice IIenkel, Assistant, Drug and Medicinal Plant Inrestiyations. 

W. W. Stockberger, E.rpert, Drug and Medicinal I'lant Investigations. 



JAN 8 1907 



V 






OF TRANSMITTAL. 



U. S. DePAKTMENT of AdlMCULXUKE, 

Bureau of Plant Industry, 

Office of the Chief, 

Washhujfo)), I). C, ADirch i20\ 100.',.. 
Sir: I lia\c the honor to truiisniit herewith and to reconunend for 
pnl)lieation as Bullethi No, 5(S of the series of this Bureau the aeconi- 
l)anvino- techiiieal paper entitled ''The Vitalit}^ and Germination of 
Seeds." 

This paper was prepared ]>y J. W. T. Duvel, Assistant in the Seed 
Laboratory, and has been submitted by the Botanist with a view to 
pul)lication. 

Respectfully, B. T. Gallow^av, 

Cliicf of Bureau. 
Hon. James Wilson, 

Sccrctarij of Agriculture. 



P R E FACE 



Bocauso of variation in tlu^ amount and ([uality of oach year's crop 
it is froiiuontly necessary for seedsmen to carry over lar^e ([uantities 
of seeds from one year to anotlier. Such seeds often lose their al)ility 
to germinate, and either are a h)ss to the seedsman or, if they arc 
marlvcted, cause still more serious losses to thos(^ who plant them. 
Since IS'J'J Mr. Duvel has l)een ongag-ed in a oeneral investigation of 
the causes afi'ecting the vitality of seeds, with special reference to the 
conditions under which tliey nvo stored conunercially. This investiga- 
tion was l)egun in IS'.I!) under the Dexter M. Ferry Botanical P\dlow- 
ship at the University of Michigan, and since Septeml)er 1, 11)02, it 
has heen contiiui(>d by the ITnited States I)(^pai-tment of Agriculture. 
An account of the whole study is presented herewith. 

The general method pursued has been to store seeds experimentally 
under all sorts of conditions, and afterward to ascertain the exact ptn-- 
centage of gin-mination. It is now possilde to speak with precision of 
the extent of damage causcnl by careless methods of storage, to expi'ess 
in actual hgures the greater liability of seeds to loss of vitality under 
the warm humid conditions (^xisting in the South Atlantic and Gulf 
States than under colder and drier conditions, and to demonstrate the 
utility of storing seeds, when they must V)e kept in a hunnd climate, in 
moisture-proof packages. A further iu\'estigation, i. e., of the extent 
to which \italitv may be preserved by means of conuuercial cold stor- 
age, is now in progress. 

Frkdkkk;k V. Coviixe, 

Office of Botanical Tnvestications and Experiments, 

WasJi!)i<jt(i))^ D. C., Deceiiibcr f>^ lUO-]. 

5 



conti^:nts. 



Page. 

Iiitrdductinn 9 

Matei'ials and inctli<i(lH 10 

Seeds 10 

(Termination tests and ai)})aratns 11 

Effect of climatic conditions on the vitality of seeds 13 

Causes of the losses in vitality in difterent climates 22 

Effect of inoistnre and temperatnre npon vitality 24 

Seeds packed in ice 26 

Effect of moisture on \ itality at iiighcr tcmpciatmes 29 

Summary 85 

Effect of delinite (juantities of moisture on the vitality nf seeds when they are 

kept within certain known limits of temperature .'56 

A comparison of methods of storinjj and shipping seeds in order to protect 
them from moistun*, and conse(iuently to insure a better jireservation of 

vitality 44 

Suggestions of earlier investigators 44 

The necessity for thoroughly curing and drying see(ls 45 

Character of the seed warehouse or storage room 46 

The value of good seed to the market gardener 46 

Shipping seeds in charcoal, moss, I'tc 47 

Nature of the experiments 47 

Disposition of the samples 48 

Results of the germination tests 50 

Experiments in keeping and shipping seeds in spcn-ial packages 65 

Respiration of seeds 74 

Sununary SI 

Enzymes in si'cds and the piart they play in the preservation of vitality 82 

Sununary 87 

Literature cited 90 



ILLUSTRATIONS. 



TEXT FICUKES. 

Page. 

Inn. 1. .\pparatus used to determine the effect of moisture and temperature on 

the vitality of seeds in communication witli free air : ;*>() 

2. Ai)]>aratus used to determine tlie effect of moisture and temi>erature 

on tlie vitality nf seeds nat in conununicatinn with fret' air oO 



B. p. T.-94. B. I. K.- 

THE \1TA1JTY AND GERMINATION OF SEEDS. 



INTRODUCTION. 

]t has long- Ijcen known tliat the conditions nndor which plants are 
grow n and the dog-ree of niaturit}' at the tinu^ of harvesting are fac- 
tors which play an important part in the life of seeds. But, granting 
that seeds are of strong vitality at the time of harvesting, there 
remain to ])e considered the methods of gathering and curing, the 
water content of the seed at the time of storing, the methods of stor- 
age, the humidity and temperatui'e of the surrounding atmosphere, 
the composition of the seed, the nature of the seed coats, activities 
within the cells, and munerous other factors which play important 
parts in the life of the seed. 

The conditions necessary for the successful germination of a seed of 
good \itality and the chemical transformations accompanying these 
carl}' stages of development have received considerable attention from 
numerous investigators. These changes and conditions are fairly well 
understood for many of our common seeds. However, several impor- 
tant facts still remain unexplainiHl, and our knowledge will not be 
complete until each and every species has Ijeen carefully studied. 

On the other hand, the conditions influencing the vitality of seeds as 
commercially handled are but little understood and hav(^ })een almost 
wholl}' neglected in research work. Likewise, but little attention has 
been given to the complex chemical and physical changes which take 
place in mature seed dui'ing the slow process of devitalization. It was 
in order to determine some of these factors that the work described in 
these pages was begun, and the results are thus of consideral)le practi- 
cal value as well as of scientitic importance. The present paper treats 
chiefly of the conditions influencing the vitality and germination of 
seeds when sul)jected to such methods of treatnuMit as are generally 
met with in the ordinary handling of seed. Particular attention has 
been given to the effect of climate, moisture, and temperature on 
vitality, supplemented with a discussion of the changes taking place 
in mature seeds, especially the respiratory activities and the part 
pla3'ed l)y euzj^mes. 

9 



10 THE VITALITY AND OEKMINATION OF SEEDS. 

Tho results of the ;il)ove experiments have sug-gested ioiproved 
niethods of stofing and shipping seeds so as to prolong their vitality 
and also to secure the production of more vigorous seedlings. 

The work for the present i)aper was ])egun in lS9i) at the University 
of Michigan and was continued for three consecutive years while the 
writer held the Dexter M. P^rry Botanical Fellowship in that institu- 
tion. During this time the investigation was under the direction of 
Prof. y. M. Spalding, Ph.D.. and Dr. F. C. Newcoml^e, who showed 
great interest in it and gave Aaluablc suggestions as the work pro- 
gressed, at the same time placing the facilities of the laboratory and 
of the lil)rary at the disposal of the writer. Since September 1, 1902, 
the work has been continued in the Seed Laboratory of the U. S, 
Department of Agriculture. Valuable assistance in storing seeds was 
rendered by Prof. C W. Burkett, at Durham, N. H. ; Mr. E. E. Smith, 
Wagoner, Ind. T. ; Prof. W. R. Dodson, Baton Rouge, La.; Prof. F. S. 
Earle, Auburn, Ala. ; Zimmer l^rothers. Mobile, Ala.; Prof. H. H. 
Hume, Lake City, Fla., and Prof. Charles B. Scott, San Juan, Porto 
Rico. 

Materials and methods. 

SEEDS. 

For these experiments thirteen diU'erent samples of seeds were used, 
being so selected as to include representatives of ten dift'erent families 
and twelve genera and species, as follows: 

Poaceix — ZeCL tiiays^ sweet corn (two samples). 

Liliaceae — Allium, cepa L., onion. 

Brassicaeex — Br<is!<lca olcr((e<'(i L., ca))bage; Ritphaitus mtvoui^ L., 
radish. 

Ap'mcese, — Dcmciis carotn L., carrot. 

Falmeex — Pisuni sativum L., pea; 7*/i(fse(j/t/s' vitlgarlx L., bean. 

Violaceai — Viola tricolor L. , pansy. 

Polemoniacese — Phlox drmnnumdii Hook, phlox. 

SolaotacecV — Lycopersicon lycoperslcnni (L.) Karst., tomato. 

Cuearhitaceai — CitruUus cltruUm (L.) Karst., watermelon. 

Asteraceie, — Lactuca sativa L., lettuce. 

It will thus ])e seen that the seeds used cover a wide range as to 
family characteristics, as w^ell as size, structure, and composition of 
seed. Likewise they are all from plants of the garden or iield that 
have undergone a high degree of cultivation, thus ena])ling the seeds 
to withstand more or less variation as to conditions of vitality and 
growth. 

All seeds used throughout these experiments were provided by 
D. M. Ferry & Co., of Detroit, Mich., and the seed furnished was of 
strong vitality and of known age and origin. The corn ''A" (Minne- 
sota Sweet), onion (Yellow Danvers), pea (D. M. Ferry Extra Early), 
bean (Yellow Kidney, Six Weeks), tomato (Dwarf Champion), and the 



MATERIALS AND METHODS. 



11 



watoi'melon (Sweet Mountain) were grown in Michigan. The corn 
''B" (Minnesota Sweet), wafs grown in Ne])raska, the ca])])age (Win- 
ningstedt), in Washington, and the h^ttuce (l^lack-Seeded Simpson), in 
California, whih> the radish (Early Scarlet Turnip-Hooted), carrot 
(Chantenay), pansy (mixed), and Phlox druiii'incnidu (mixed) were 
grown in France. The seed was all of the harvest of 1890 and was 
received at the l)otanical laboratory of the University of Michigan on 
January 27, 1900. 

On January 30, 1900, germination tests were made, showing the 
vitality of the seeds to be as follows: 

Vitality of seeds tested January 30, I'jOO. 



Kind of seed. 


Percent- 
age of 
germina- 
tion. 


Kind of seed. 


Percent- 
age of 
germina- 
tion. 


Bean 


100 


Pansy ti'.l. 5 




93 


Pea '.)7 




83.5 
94 

88 

87.5 

98 


Phlox 


7.S 

SI 




Radish 




Tomato . . . 


98 




Watermelon 


99 


Onion 











GERMINATION TESTS AND ArPAHATUS. 

In the preliminary work several methods of testing were tried, but 
as none proved as serviceable as the ''Geneva tester," this apparatus 
was adopted for all subsequent tests as recorded in the following- 
pages. The detailed construction of this tester need not be descril)ed, 
for it is simple and quite familiar to all. However, some nioditications 
were made in the preparation of the apparatus, and some precautions 
taken in the manipulation, which have proved to be of much value. 
The brass wires originall}' and ordinaril}'^ used to support the folds of 
cloth were replaced by glass rods of (I to T mm. diameter. Rods of 
this si>5e are mucli heavier than is necessary to support the folds of 
cloth, but the chief advantage in having rods of large diameter is that 
in case of the germination of large seeds the folds can be drawn near 
together at the top and still have sufficient space within the fold for the 
seeds. On the other hand, in the germination of small seeds that 
require considerable^ ((uantities of air, the folds can be closed at the 
top ])}' bringing the rods together, thus insuring more uniform condi- 
tions throughout the fold and at the same time leaving sutlicient space 
above the seeds for an a])undant supply of air. The chief advantage 
in substituting glass rods for brass wires is in removing the possible 
source of injur}- resulting from the poisonous action of the dissolved 
copper. 

Another error f requentl}', if not alwa^^s, made in using such a tester 
is in allowing the ends of the cloths, or sometimes the bottoms of the 



12 THE VITALITY AND GERMINATION OF SEEDS. 

folds, to dip into water in the pan. This should never be permitted, 
for in that wa}" seeds are kept too moist, especially near the ends of 
the folds. Likewise such methods o-ive an opportunity for the trans- 
mission of dissolved copper and a resulting;- injury to the seeds. For 
this same reason the strips of cloth should be made sufficiently narrow 
not to come into contact with the sides of the pan. 

Much better results are ol)tained if the seeds, before being placed 
in the germinator, are soaked in water for several hours, the length 
of time depending on the power of absorption of the seeds. In these 
experiments the seeds were always soaked in distilled water for twelve 
or fifteen hours before transferring them to the germinator. This 
preliminary soaking gives a more speedy germination, which is always 
advantageous, especially in making comparative germination tests. 
In order to supply the requisite amount of moisture for subsequent 
growth, the cloths were first uniformly and completely wet with dis- 
tilled water; moreover nuich care was taken to see that there was only 
a very small quantit}^ of water in the bottom of the pan. In case of 
seeds that germinate readily, such as cabbage, lettuce, and onion, it is 
necessary that all surface water be removed from the bottom of the 
germinator if good results are desired. The pan then being covered 
with a glass plate, it is seldom necessary to increase the amount of 
moisture, for seeds when once soaked need only to be kept slightly 
moist and not wet, as must necessarily^ be true if the ends of the cloths 
or l)ottoms of the folds dip into the water. After soaking, the water 
in the seeds and cloths is ample for the completion of most germina- 
tion tests. However, in an occasional test the seeds may become 
slightly dry, which happens when the cover is kept off the pan for a 
considerable time while counting germinated seeds. In such cases the 
remedy is to pour a small quantity of water in the bottom of the pan, 
or in extreme cases to moisten the folds with a fine spray. 

If the above modifications be adopted and the necessary" precautions 
taken, many of the objections frequently made to the Geneva tester 
will be removed and the difficulties will be overcome; at least it is a 
most excellent method of testing seeds where comparative results are 
especially desired. It must also be borne in mind that the Canton flan- 
nel (which is generally used in making the pockets) should ahva3\s be 
of the best grade and should never be used a second time without l)eing 
thoroughly cleaned and sterilized. 

In selecting samples for germination the impurities and the imma- 
ture seeds were first removed. The samples for test were then made 
up of the remaining large and small seed. For the most part 200 
seeds were taken for a test, hut with the larger seeds — corn, pea, bean, 
and watermelon — 100 seeds were usually used. In all cases where any 
irregularity was apparent, tests were repeated. The controls are 
based on the results of several duplicate tests. 



EFFECT OF CLIMATIC CONDITIONS. 13 

All germination tests were made in a dark room where the temper- 
ature could be comparative!}' well regulated and was maintained nearly 
constant throuohout most tests. Germiniited seeds were removed dai 1 y 
during early stages of the tests and a com]>lete record of the munher 
germinating each day was kept. Tliis is of value in seed testing, 
because the germinative energy of a seed tells nuich as to its vitality. 
If seeds have a high vitality, the germinative energy will l)e very 
strong, i. e., germination will take place rapidly, giving rise to strong 
and vigorous seedlings; )>ut if the seeds are of very low vitality, there 
will l)e a corresponding retardation in germination, giving rise to 
weak seedlings, i. e., showing a low germinative energy. In most 
cases throughout this work only the tinal percentages of germination 
are tabulated. 

EFFECT OF CLIMATIC CONDITIONS ON THE VITALITY OF SEEDS. 

It has long since been known that seeds under ordinary conditions 
lose their power of germination after the lapse of a few years, or in 
some cases within a few weeks or months. Many investigators have 
also learned that the rapidity with which seeds lose their vitality, when 
stored under ordinary conditions, ^'aries greatly with the; section of 
the country in which such seeds are kept. This loss in vitality is espe- 
cially marked in the case of seeds stored in places of relatively high 
humidit}'. The rapid deterioration of seeds in localities having a 
humid atmosphere has become a source of much embarrassment to 
seedsmen, for they have experienced many difficulties in shipping seed 
to such places. This is especially marked in the case of seeds sent to 
growers or dealers in the vicinity of the Gulf of Mexico. Gardeners 
and planters in that part of the United States are continually com- 
plaining about the nonvial)h', seeds sent out l)v seedsmen. Some grow- 
ers have learned how to guard against this difficulty to a certain extent. 
Zimmer Brothers, of Mobile, Ala., wrote, on Feljruary 2S, 11)00, con- 
cerning this matter, as follows: 

During thirty years' experieni'e in market gardening, we have iearneil tliat .seeds 
of many hardy plants will not keep in our climate, and when ordering we so time 
our order that we can plant the seeds as soon as received. If such be impossible, we 
are very careful to keep the original 2>aekage unopened until conditions are favorable 
for planting. If we find it necessary to keep seeds of hardy plants for some months, 
we put them uj) on arrival in dry bottles, put on toj) a bit of cotton saturated with 
chloroform and cork tightly. AVe have kept, in that way, cauliflower seed satisfac- 
torily for twelve months. At the shore seeds keej) very badly; one-half mile back 
they do much better. As a rule seeds of tender ]>lants give but little trouble. 

As far as has ])een ascertained, no definite experiments have been 
made with these points in view, and especially with the idea of deter- 
mining the cause or causes of this deterioration of \ ital energy. In 
order to obtain reliable data on these points, a series of experiments 
was undertaken in Fe))ruary, 1900, to determine how seeds are atiected 



14 THE VITALITY AND GERMINATION OF SEEDS. 

when cli(stri))uted to dirterent parts of the United Stute.s iindsu]>niitted 
to the free influence of various climates. Likewise at the vai'ious 
points where tests were made the seeds wore subjected to diflerent 
treatments. 

The phices selected for these tests were San Juan, P. R., LakeCit}", 
Fla. , Mobile, Ala. , Auburn, Ala. , Baton llouge, La. , Wagoner, Ind. T. , 
Duj'ham, N. IL, and Ann Arbor, Mich. 

A sample of each species of seed was put up separateh' in double 
manila coin envelopes and in closely corked bottles. Dujilicate sets 
of each series w^ere then subjected at each of the above-named places 
to the following' conditions: 

Trade c(m(1!tt(ms.^Con^\i\oi\ii similar to those in which seeds are 
kept when offered for sale by retail dealers, the seed being- more or 
less exposed to meteorological changes and su])jected to natural varia- 
tions in temperature and humidit3^ For the most part the seeds were 
in rooms that were never heated. 

Dry rooms. — Rooms in the interior of buildings which were artifi- 
cially heated during cold weather, and where the quantity of moisture 
was relatively small and the temperature comparativel}^ constant. 

Bamments. — Rooms where the temperature was comparativel}^ low^ 
and uniform, and the relative humidity of the surrounding air was 
much higher than in "trade conditions" and "dr}^ rooms."" 

These conditions varied in the different places at which tests were 
made, and a more detailed description will be given when the results 
of the germination tests are discussed. 

For the first part of this paper, treating of the influence of climate 
on vitality, none of the seeds need to be considered save those pre- 
pared in paper packages and kept under trade conditions, these coming 
more nearly under the direct action of the surrounding atmosphere. 
A sample of each kind of seed was put up in a manila (No. 2) coin 
envelope, and each of these packages was then inserted in a second 
(No. 3) coin envelope. Duplicate samples of ever}^ kind of seed were 
sent to the A^arious testing places, where they Avere su])jected to trade 
conditions. At San Juan the packages of seeds were kept in an open 
room, being siil)jected to the full action of the atmosphere but pro- 
tected from the direct rays of the sun and from rain. At Lake City 
the packages were kept in a one-story frame building which was not 
artificially heated and the doors of which were open the greater 
portion of the time. At Mobile the packages of seeds were stored in 
a comparativel}" open attic of a private dwelling. At Auburn the 
seeds were stored in a greenhouse office, with the doors frequently 
standing open. At Baton Rouge the packages were kept on a shelf in 
a grocery store, the doors of which were closed only during the night. 
At Wagoner the conditions were very similar to those of Baton Rouge, 
save that the packages of seeds were kept in a drug store. At Dur- 
ham the seeds were kept over a door at the entrance of one of the 



KFFKCT OK CLIMATIC CONDITIONS. 



15 



colleg'e l)iiil(liii_ii;'s. 'Plii.s door opens into :i hall wliicli coinnuniicatcs 
witli the ottices, cheniiciil I:il)orat()iT, and the basemeiit. At Ann 
Ar])or the seeds were stored in the Itotaiiieal laboratory, with slightlj 
varj'ino- conditions, they bein^- near a window whicli was fre([uently 
open durinio" the suminer. and at irre<^ular intei'\als during- the early 
part of the sunnner the packages were placed in the window so as to 
receive the diiect rays of the sun. The seinls stored at Ann Ai'bor 
served partially as conti'ols for those sent to tlu^ ^•arious otluM' places, 
and, in addition to the last-named series, seeds from tht^ original 
packag'es, as received from I). M. Feriy c'v: Co.. wei'c kept in a dry 
and comparatively^ cool closet on the fourth floor of the botanical lab- 
oratory. These seeds served as checks for tlu^, complete set of exper- 
iments, and arc designated throughout this paper as "C'ontrol.'' 

The samples were sent out to the al)Ove-ir.im(ul places in February, 
1900. The first conn)lcte set was returned in fFune, or early July, of 
that year. The second complete set was allowed to remain throughout 
the entire sunnner, and was returned in October and eaily November 
of the same year. The average time of treatment for the two series 
of experiments was 12S and 251 days respectively. ANhen the seeds 
were returned, germination tests were made as soon as possible. The 
length of time that the seeds were in the various places and the vitality 
as shown by the gei'mination tests are given in Tables I and 11. In 
both tables the colunms from left to right, })eginning with Mo))iIe, 
Ala., are in the order of the degree to which the seeds were injured. 

Tahle I. — l^jffect of rliiiidli' on luto/ili/, <(.s shoii'ii hij prrceiihtf/c of ijennliiatioii — ;///-.s7 test. 



Kind of seed. 



Corn, sweet, "A"... 
Corn, sweet, "B" .. 

Onion 

Cabbage 

Radish 

Carrot 

Pea 

Bean 

Pansy 

Plilox drumniondii. 

Tomato 

Watermelon 

Lettuce 



Average of all seeds 



Con- 
trol. 



Mobile, 

Ala., 
Feb. 17 

to 
.Iulv7. 

lio 

davs. 



San 
Juan, 
P. R., 
Feb. 9 

to 
rune 20. 

days. 



90. 
72.0 
S4. f, 
.S2. 
(i 1. 
71. f) 
91.0 
100.0 
•20. 
23. r, 
94.0 
90.0 
79.0 



7.=). 12 



Baton 
Rouge, 

La., 
Feb. 17 

to 

JunelS. 

121 

days. 



96. 
80. 
90. 
8S. 
77. 
71. 
94. 
90. 
2.S. 
47. 
91. 
100. 



Wagon- 
er, 

Ind.T.. 

Feb. 17 
to 

.Iune23. 

120 

days. 



Lake 
City, 
Fla., 
Feb. 9 

to 

JunelS. 

129 

davs. 



96.0 
70.0 
93. .'■) 
.S3. T) 
77. f) 
SI . f) 
9S. 
90. 
4S. .'•) 

50. r, 

90. 5 
98. 
7S.0 



82. 12 



94.0 
80. 
95. 
89. 5 
79. 

90.0 
98. 
41.5 
41.5 
94.0 
98. 
87. 



.S3. 00 



Dur- 
ham, 
N. H., 
Feb. 17 

to 

Julv 14. 

147 

lavs. 



100. 

89. 3 

90. 5 
93. 
SO. 
78.0 
98. 

100. 
.55. 5 
07. 
94. 5 
98.0 
82. 



Au- 

l)urn, 

Ala., 

Feb. 17 

to 
May 30. 

102 
davs. 



90. 
8,S.0 
9(!. 
91 . 
75. 5 
Si. 5 
93. 3 
9S. 
57. 5 
01. 5 
95.0 
94.0' 
SO. 5 



Ann. 
Arbor, 
Mich. 



100.0 
92. 
9.5.0 
90. 
.82. 5 
70. 
90. 
98. 
53. 5 
07.0 
89.0 

100.0 
82.0 



85. 57 



.85. 70 ,80. 23 



From Table I it will be seen that the loss of vitalit}' in the case of 
seeds stored at Mobile was much greater than in those stored at any 
of the other places. The greatest loss in the samples tested was in the 



16 



THE VITALITY AND CIEEMINATION OF SEEDS. 



phlox, where the <^ernun!itioii was only 0.5 per cent, or a Uj.ss in vitality 
of 1)9.3 per cent as compared with the control. These results were 
closelj' followed by a lo^s in vitality of 1>.5.1> and 92. T per cent for the 
pansy and onion seed, respectively. The percentages of germination 
in the other cases, except the "B"" .sweet corn, pea, and bean, were 
sufficient to have produced a fair stand, i. e., if we consider that far 
too -many seeds are usually sown. But a decrease in the percentagH; 
of germination means seeds of a low germinative energy. Even 
though the tinal percentage of germination be up to standard, the 
retardation may l)e of vital importance. A very good example of the 
retardation in germination is shown in the tests of the watermelon 
seeds. In the control sample 94 per cent of the seed germinated in 
472^ hours, while the seed returned from Mobile showed, during the 
same time, a germination of only 13 percent; yet the difference in the 
hnal germination w'as only 0.3 per cent in favor of the control. Like- 
wise the seed returned from San Juan germinated only 30 per cent in 
47^ hours, the final germination being 90 per cent or only 2.3 per cent 
lower than the control. 

Many similar cases might be mentioned in which the final per- 
centages of germination, as shown by the first set of tests given in 
Table I, represent a loss such as might be justly considered well within 
the limits of normal variation. However, that all of the samples of 
seed were injured as a result of the unfavorable climatic conditions is 
shown in the second set of tests set forth in Tal)le JI. In the latter 
case the seeds remained in the \arious places nearly twice as long as 
those used for the first test. 



Table II. — Effect of climate on vitality an t^howii hi/ 2>ercentage of (jerrn'mation — second test. 



Kind uf seed. 


Con- 
trol. 


Mobile, 

Ala., 

Feb. 17 

to 
Nov. 6. 

262 
days. 


Baton 
Rouge, 

La., 
Feb. 17 

to 

Get. 22. 

247 

days. 


Dur- 
ham, 
N.H., 
Feb. 17 

to 
Oct. 26. 

251 
days. 


Au- 

bTirn, 

Ala., 

Feb. 17 

to 

Nov. 19. 

275 

days. 


Lake 
CMtv, 

Fhi., 
Feb. 9 

to 
Oct. 1. 

234 
days. 


Wag- 
oner, 
Ind. T., 
Feb. 17 

to 
Oct. 13. 

238 
days. 


San 

Juan, 

P.R., 

Feb. 9 

lo 

.Tune 20. 

129 

days. 


Ann 
Arbor, 
Mich. 


Corn, sweet, "A" 

Corn, sweet, " B " 

Onion 


91. 5 
,S,H. 5 
97. 

92. 4 
7s. s 
,S2. 
9.'). 7 
9.H. 7 
r.3. 
53. 9 
97. 5 
99.0 
92.3 


20.0 

12.0 

0.0 

17.0 

51.0 

8. 5 

44.0 

0.0 

0.0 

0.0 

79. 5 

(-.4. 

20.0 


88. 

51. 2 

0.5 

25. 
80.0 
GO.O 
0.0 
0.0 
90.0 
92. 
84. 5 


96. 
82. 

0.0 
12.0 
59. 5 

2.0 
91.0 
78. 

0.0 

0.5 
87.0 
82.0 
88. 5 


88. 
62. 
12.0 
61.5 
63.0 
36.0 
97.9 
56.0 
2.0 
1.0 
94. 
86.0 
86.0 


92. 
77.0 
16.5 
63. 5 
58. 5 
43. 5 
86. 5 
84.0 
1.5 
2.5 
94.0 
92.0 
85.0 


90. 
78.0 
21.5 
70. 5 
(iO. 5 
49. 
80.0 
82. 
7.5 
5.5 
94.0 
94. 
82. 


92. 

78.0 
50. 
76.2 
62. 
48. 5 
98.0 
96.0 
6.5 
11.5 
96. 5 
88. 
83. 5 


98.0 
80.0 
97.5 


Cabbage 


91.0 




77. 5 




86.0 


Tea 


98. 
100.0 




46.5 


Phlox dnimmondii 

Tomato 


40.0 
98.0 




96.0 


Lettuee 


92. 5 


Average of all seeds . 


8(5. 77 


24. 31 


50.86 


52. 42 


57. 34 


61.27 


62.11 


68.21 


84.. 58 



KFFKCT OK PLIMATIC CONDITIONS. 17 

Im'cii thouyli tlu' eoluiniis ill ])otli Tu])los I and II uro !iiT:iiii;<'d in 
t!ic> order of the loss in vitality as shown )>y tiu^ a\(M'a<i'es of the 
\aiious places, it will at once ])e seen thattlu^ relati\e deoi'(H> of injury 
did not remain tliesanie tlirouo-hoiit the ex])eriinent. This is pi'olnibl}^ 
best explained ])y a variation in the climatic inlluences. It is evident 
that in some of the places where seeds were stored the eti'ects were 
more deleterious duriuL;- the time between the tirst and second tests 
than they were during the lirst period of stora^'c of It^S days. The 
results given in Table II arc of the greater value in showing the 
r(dative merits of the dilferent localities as ])laces for storing seeds, 
extending aA the}' do over a longer period of time. 

As a result of the second series of tests itw'as found that the average 
percentage of germination of all of the samples of seed that were 
stored in trade conditions at Mobile for 202 days was oidy 24:. HI per ccMit. 
This is equivalent to a loss in vitality^ of Tl.'.KS per cent as compai'ed 
with the average percentage of germination of the control samples, the 
average germination of the controls being S(). 77 per cent. The pansy, 
phlox, onion, and beans stored at Mobile wholly lost their power of 
germination. The tomato seed, which proved to ])e the most resistant 
to unfavorable conditions, gave a germination of 7t).5 per cent, or a 
loss in vitality of 18.46 per cent, as compared with the control sample, 
which germinated 97.5 per ciMit. The degree of deterionition in the 
seeds stored at the other places was much less marked than for those 
stored at Mobil(\ Th(» loss in vitality was only 4L.o!> per cent in the 
s(H'ds retui'ned from Baton llouge. The results from the seeds which 
were stored at Durham, Aui)urn, Lake C-ity, Wagoner, and San fJuaii 
diti'ered 1)ut little from those from Baton liouge. The ivlative losses 
in vitality are in the order given. The seeds k('i)t in the packages 
which were stored inider trad(- conditions in the lal)()i'at()ry at the 
CJniversity of Michigan showed a loss in a itality of only 2..'>2 per cent 
as compared with the control, the seeds of which wen^ stored in a cool, 
dry closet on the fourth Hoor of the botanical laboratory. Ordinarily 
a loss of 2.52 per c(Mit would 1)e considered as a normal \ariation due 
to sampling and testing, and such was ])i'()bai»ly true in these two sets, 
with the exception of the greater deterioration of the phlox, pansy, 
and '"B" sweet corn, wdiich were undoubtedly injured by the unfa- 
vorable trade conditions, as repeated tests have shown. 

From Table II it will also be seen that the ^'A'' sweet corn, peas, 
tomato, and watermelon, with the exception of tiiose returned from 
Mol)ile, show a fair percentage of germination. In some cases the tinal 
percentages of germination were even higher than tlie controls; but, as 
previously stated, the tinal germination is not always a good criterion 
for the determination of vitality, it Ijeing necessary to consider the 
germinative energy as a l)asis foi- comparison. In order to show this 
moi'C fully some of the dc^tailcd results arc hc^rewith gi\'en in Table III. 
These I'esults show' to a good ad\'antage the degree to which germina- 
tion has been retardcnl. 

25037— No. 58—04 2 



18 



THE VITALITY AND OERMIISTATION OF SEEDS. 



Tahi,k til — RtittrddlKin in (jeriiibtation due t< 

cuiiditioiii 



iijiiri/ 



d III/ imfarorable clbnnt'ic 





Corn "A." 


Peas. 


Watermelon. 


Tomato. 


Place where seeds 
were kept. 


(iermi- 
nation 
at end 
of 64 
hours. 


Final 
germi- 
nation. 


Germi- 
nation 
at end 
of 40 
hours. 


Final 
germi- 
nation. 


Germi- 
nation 
at end 
of 84 
hours. 


Final 
germi- 
nation. 


Germi- 
nation 

at end 
of 88 
hours. 


Germi- 
nation 
at end 
of 107 
hours. 


Final 
germi- 
nation. 


Control 

Mobile, Ala 

San Juan, P. R 

Baton Rouge, La . . 
Wagoner, Ind. T . . 

Lake City, Fla 

Durham, N. H 

Auburn, Ala 

Ann Arbor, Mich.. 


Per cent. 
SL3 
4.0 
64. 
.50. 
64. 
68. 
86. 
81). 
82.0 


Per cent. 
94.5 
20.0 
92.0 
88.0 
90.0 
92.0 
96.0 
88.0 
98.0 


Per cent. 
79. (i 

" 24. 
60.0 
36.0 
36.0 
50.0 
54.0 

It 93. 7 
82.0 


I'er cent. 
95. 7 
44.0 
98. 
80. 
,S0. 
86. 
94.0 

97. 9 

98. 


Per cent. 

98. 
0.0 

12.0 
0. 
2.0 
0.0 
0.0 

22. 

94. 


Per cent. 
99. 
64. 
88. 
92.0 
94. 
92. 
82.0 
86.0 
96.0 


Per cent. 
78.0 

1.5 
3.S. 5 

9.0 
40.0 
16. 5 

0.5 
59.0 
75. 5 


Per cent. 
92.7 
12. 5 
78.0 
56. 
81.5 
65.0 
5.5 
75.5 
91.0 


Per cent. 
97. 5 
79. 5 
96. 5 
96. 
94.0 
94. 
87.0 
94.0 
98.5 



"After 62 hours. 

In order that the results of Ta)>les I and II ma}" 1)0 more readily and 
fully comprehended, it has been deemed advisable to summarize them 
in another ta])le. For this purpose the average percentages of germi- 
nation of all of the diflferent samples of seed have been determined for 
each of the different places. From these average percentages of ger- 
mination the deterioration in vitality, as shown l)y both the first and 
second tests as given in Tables I and II, have been calculated, the ger- 
mination of the controls serving as a ])asis for comparison. These 
results furnisli more trustworthv data as to the relative merits of the 
different localities as places for storing .seeds. Likewise the per- 
centages of deterioration between the time of the tirst and the second 
tests are shown in Table IV. 

Table IV. — Average percentages of germination of all seeds kept at the various places, their 
deviations from the controls, and the increased jjercadages of loss in the second series of 



Place of storage. 



Control 

Mobile, Ala. 



San Juan, P. R . 



Baton Rouge, La . 

Durham, N. H 

Auburn, Ala 

Lake City, Fla. . . . 
Wagoner, Ind. T . 
Ann Arbor, Mich. 



Average germina- 
tion of all seeds 
used in experi- 
ments. 


Deterioration in 
vitality as com- 
pared with con- 
trols. 


First test. 


Second 
test. 


First test. 


Second 
test. 


Per cent. 


Per cent. 


Per cent. 


Per cent. 


87. 79 
53. 59 


86. 77 
21. 31 






38. 95 


71. 98 


...j 


68.21 
'< 4.5. 18 


( ,..{ 


21.39 
" 47. 93 


80.48 


50. 86 


8.32 


41. 39 


85.57 


52. 42 


2. .52 


39. 58 


85.70 


.57. 34 


2.38 


33.91 


83. 00 


61.27 


5. 45 


29. 38 


82. 12 


62. 11 


6. 45 


28. 11 


86. 23 


84. 58 


1.77 


2. .52 



Deterio- 
ration in 
vitality 
between 
first and 
second 
tests. 



Per cent. 

1.16 
51.61 

9. 20 
"39.86 
36.81 
38. 74 
33.10 
26. 18 
21.37 

1.91 



a Calculated results. 



EFFECT OF CLIMATIC CONDITIONS. 19 

III 'riil)le TV the results ufe arnuio-od in the order of tlic loss in vitul- 
ity as shown by the second tests. However, a few words of explana- 
tion will bo necessary, especially concernino- the loss at San Juan. In 
the first place, the seeds were kept at San Juan only J?>1 days" during 
the early part of the sunnner, while durino- the most critical period, 
Jiuie 20 to Noveni))er (!, they were in the ))otanical laborator}' of the 
University of Michigan. Those marked Mobile, Ala., were, during- 
the entire time, 2<>2 days, under the iuliuence of the warm, moist cli- 
mate of the Gulf of Mexico. The seeds kept at other places can well 
be compared with those from Mobile, the time being approximate 1}^ 
the same. The average loss as shown l)y the second tests was 3.35 
times greater than the loss in the first test, which by calculation would 
bring San Juan next below Mobile, witli a loss of vital energy in the 
seeds ecpial to 47.93 per cent. But more data are necessary l)eforc 
such a gradation of injurious climatic influences can ])e established. 

Talkie IV, however, brings out another interesting point, as shown 
by comparing the results of the first and second tests at San ,Tiian and 
Mobile. In the first test the loss in vitality of the seeds from Mobile 
was 3S.9.5 per cent, while the seeds returned from San Juan showed a 
loss of only 14.31 per cent as compared with 71.98 and 21.39 per cent, 
respectively, as shown in Table II. The degree to wdiich the seeds 
were injured while they were stored in San Juan was such that the}^ 
continued to deteriorate nuich more rapidly than the control sample. 
This deterioration was most marked in tlie case of the pansy seed, the 
germination of the first test being 20 per cent and that of the second 
test only 6.5 per cent, showing a loss in vitality of 68.2 per cent and 
87.7 per cent, respectively. Thus when seeds are once placed in con- 
ditions unfavorable for the preservation of their vitality for a sufficient 
length of time to cause some injury, this injury will alwaj's l)e mani- 
fest and cause a premature death of the seeds even though they after- 
wards be removed to more favorable conditions. 

Seeds of strong vitality can witlistand greater changes in conditions 
than seeds of low vitality without any marked detei'ioration. Through- 
out these experiments a wide difference has t)een observed l)etween 
the ''A'' sweet corn and the ''B'' sweet corn. The oi'iginal tests 
made «Tanuary 30, 1900, at the time the seeds were received, showed a 
germination of 94 per cent for the "' A'' sample and <SS per cent for 
fhe "B" sample of corn. The control tests, made in November, 1900, 
showed a germination 0.5 per cent higher in each case; but the average 
loss ill vitality of the two samples of seed kept at the various places 
was 12.17 per cent for the ''A'' sample and 26.10 i)er cent for the "■ B" 
sample. As with the pans}^ and the phlox these samples showed that 



"The number of days here given for Sau Juan is not absolutely correct. The time 
was reckoned from the date the seeds were sent from the laboratory until they were 
received in return. 



20 



THE VITALITY AND GERMINATION OF SEEDS. 



the .stronger the vitality of the original .sample of seed the more harsh 
treatment can be undergone without l)eing injured. Strong vitality 
implies long life as well as vigorous seedlings. 

Another very important factor to be considered in the handling of 
seeds is the relative resistance of seeds of various species to ad\'erse 
conditions. Certain seeds under one set of conditions may retain 
their vitality exceedingly" well, while seeds of other species of plants 
under identical conditions may be killed in a comparatively short time. 
For this reason no general rule can ])e laid down for the preservation 
of seeds. Table V shows the varying degrees of deterioration of the 
different species of seeds used in the experiments. 

Table Y. — Different degrees of deleriordtion of rarioiift kinds of seeds. 



Kind of seed. 



Tomato 

Pea 

Corn, sweet, "A" . . 

Watermelon 

Lettuee 

Radisli 

Corn, sweet, "B" . 

Bean 

Cabbage 

Carrot 

Onion 

Pansy 

Plilox drnmniondii 



Fir.st test. 



(iermi- 
nation of 
control. 



Per cent. 
95. 5 
95. 3 
95. 9 
98. 3 
81. G 
83. G 
89.3 
98.7 
92.7 
83.3 
95. 8 
63.0 
69.0 



Average 
germi- 
nation 

from the 
various 
places. 



Per cent. 
93. OG 
91.. 56 
91. 75 
97. 75 
80.00 
74. 38 
7.S. IG 
93. 00 
86. 00 
75.16 
8'2. 18 
38. 87 
4-J. 87 



Deterio- 
ration in 

vitality 

as com- 
pared 
with the 

control 
samples. 



cr cent. 
2.55 
3. 92 
1.20 
.,57 
1.9G 
11.02 
12. 47 
.5.76 
7. 22 
9.77 
15. 26 
38.33 
34.97 



Second test. 



Germi- 
nation of 
control. 



Per cent. 
97.5 
96.7 
94.5 
99.0 
92.3 
78.8 
88.5 
9.S.7 
92. 4 
.S2. 
97.0 
53.0 
,53. 9 



Average 
germi- 
nation 
from the 
various 
places. 



Per cent. 
92. 43 
84. 80 
83. 00 
,S6. 62 
77. 75 
60.93 
65. 40 
G9. .50 
,52. 15 
37. .81 
25. 12 
8. 00 
7.62 



Deterif>- 
ration in 
vitality 
as com- 
pared 
with the 
control 
samples. 



Per cent. 
5.20 
11.39 
12. 17 
12. .51 
1.5.77 
22. 67 
26. 10 
29. 58 
43.56 
.53. 89 
74.10 
84. 90 
85. .85 



In the above table the list of seeds is arranged in the order of their 
power to withstand the action of diverse climati(; conditions, as shown 
by the results of the second test, given in Table II. Tomato seeds 
were found to be the most resistant, the control .sample germinating 
97.5 per cent. The average germination of the samples of tomato seed 
kept at the various places was 92.1:3 per cent, or a loss in vitalit}' of 
only 5.20 per cent. The seed showing the next least injury was the 
peas, with a deterioration of 11.39 per cent. The phlox, which was the 
most affected by the unfavorable conditions, germinated only 7.62 per 
cent, thus showing a loss in vitality of 85.85 per cent. 

It is also interesting to note that the order, as show^n by the second 
series of tests, is quite different froiu that of the first. This lack of 
uniformity increases the ditticulties that must be overcome before the 
causes of the loss of vitality in seeds can be fully comprehended. Were 
all seeds affected in the same way when subjected to identical con- 



EFFECT OF CLIMATIC CONDITIONS. 



21 



ditioiis, tho oihIci- should lia\e rciimiticd tlic sMinc throu^'hout, l>ut tho 
witlc variiitioii in :itiii().s[)lierir cliiin^cs iiirccts dillVrciit seeds so very 
diti'erently tluit no unil'onnity of I'esultsean I)(^ secured. For example, 
the conditions prevailin*^- from FeI)ruaiT until June were uuich more 
disastrous to the vitality of the tomato and pea than to the "A''' sweet 
corn, watermelon, and lettuce, while the conditions existing' from June 
to November were more injurious to the "A" sweet corn, watermelon, 
and lettuce. An examination of the table will show other results 
of a similar nature. During the earlier stagcss of devitalization seeds 
undergo a gradual deterioration in vitality, but after reaching a cer- 
tain stage in their decline there is a comparatively sudden falling otf, 
and seeds, except perhaps a few of the most persistent, soon cease to 
show any power of germination. Such factors as these must be taken 
into account in determining the relative length of tiim^ that ditferent 
kinds of seed will retain their vitality. But as yet sufficient informa- 
tion is lacking in order to make any trustworthy attempt to classify 
seeds in respect to their viable periods when subjected to different con- 
ditions. Numerous experiments are now under way, with the hope of 
furnishing a basis for such a classification. 

In order to o])tain more data as to the influence of climate upon 
vitality additional samples of seed were sent to Mobile and Baton 
Rouge, where they were stored under the same trade conditions as for 
the former experiment. For these tests only cabliage, lettuce, and 
onion seeds, put up in envelopes, as for the previous tests, were used. 
The diti'erent packages of seed, ]:)laced in paper boxes from which 
they were not removed, were sent from the laboratory on May 20, 
1901, and were returned November 20, 1901, the total time of storage 
being 190 days. The results of these tests are shown in Table VI, and 
are even more striking than those of the former tests shown in Tables 
I and II. 



Table VI. — ■Reldtirr uwrils of Mohilc, Ala., Baifni Roiu/r, La., (ind Ami Arhor, Midi., 

«.s' jthiccx fur diiriiKj xceih. 

[Period, 190 days.] 





Cabbage. 


Lettuce. 


Onion. 


Seeds subjected to 
''Trade condi- 
tions." 


Tercentage of seeds 
germinated at tlie 
end of — 


Percentage of .seeds 
germinated at tlie 
end of — 


Percentage of seeds germinated 
at the end of— 




36 
liours. 


GO 
hours. 


14 
days. 


3G 
hours. 


60 
hours. 


11 

days. 


60 
hours. 


84 
hours. 


108 
hours. 


14 
days. 


Mobile, Ala 

Baton Rouge, La . . 
Ann Arbor, Mich.. 


0.0 
0.0 
10.0 


0.0 
0.0 
(il. f) 


S.5 
2'1. 5 

m. 5 


■ 

0.0 
'J. .s 
(17.0 


1^,0 
3'.. 5 

,S2. .S 


64.0 

74.0 


0.0 
0.0 
3.0 


0.0 
0.0 
10.0 


0.0 
0.0 
43. 


0.0 

0.0 

93.0 



Table VI shows quite clearly the deleterious action of the warm, 
moist climate of the Gulf of Mexico on the life of seeds. The onion 
seed which was stored at Mo])ile and Baton Rouge did not germinate, 



22 THE VITALITY AND GERMINATION OK SEEDR. 

while soed from the .same lot stored at Ann Arbor oei-niinated '.)?> per 
cent. The cal)l)ao'(' seed was injured nearly as mueh as the onion, the 
sample from jNIobile g'erminating- only 8.5 per cent. The conditions 
at Baton Rouge were slightlj^ more favorable to the preservation of 
vitality. The calibage seed stored at the latter place g-erminated 22.5 
per cent, while a like sample of seed stored at Ann Arlior g-erminated 
80.5 per cent. The lettuce was much more resistant than eithei- the 
cabbage or the onion seed, Init here, too, the injury was ([uite marked, 
especially as shown by the retardation in germination. The conditions 
at Mo])ile wen^ also the most disastrous for the lettuce seed. During 
the first 3() hours that the tests were in the germinating chamber none 
of the lettuce seed from Mobile germinated, while the seed from the 
corresponding- sample from Ann Arbor germinated 07 per cent. The 
final percentages of germination were Ott and 90. 5 per cent, respectively, 
for the seed from Mobile and Ann Arbor, showing a loss in vitality of 
33.68 per cent in the seed stored at Mol)ile. Here it will be seen, as in 
Table V, that the onion seed was most sensitive and the lettuce seed 
most resistant to the unfavoral)le conditions. In the first tests shown 
in Table V the average loss in vitality of the lettuce, cabbage, and 
onion was 15.77, 43.50, and 74.10 per cent, respectivelv, while for the 
last tests, as shown in the foregoing table, the losses in vitalit}^ of 
similar samples of seed kept at Mol)ile were 33.08, 91.29, and 100 per 
cent, respectiA"eh\ The ratio is practically the same in l)oth cases, the 
loss in the cabbage seed being- 2.7 times greater than that of the lettuce. 
The foregoing- data are suflicient to indicate that climatic infiuences 
play a very important part in the life of seeds, and that the degree of 
injury varies greatly in difi^erent places and likewise in different seeds. 
Some seeds were practically worthless after an exposure of four or five 
months in such places as Mobile, Baton Rouge, or kSan Juan, as shown 
in Table I. After longer exposures, six or nine months, similar results 
were oljtained from all of the places to which seeds were sent. Man}^ 
of the seeds were killed, as shown in Table II. The conditions at 
Mobile were fatal to all of the seeds; that is, the seeds were worthless 
so far as the gardener is concerned. 

CAUSES OF THE LOSSES IN VITALITY IN DIFFERENT CLIMATES. 

Having shown that seeds lose their vitalitv uiuch sooner in some 
localities than in others, the question naturally arises, '"Why this 
loss in vitalit}^?" Unfortunately only two of the places where seeds 
were stored. Mobile and San Juan, have Weather Bureau stations which 
are equipped for making complete observations of the meteorological 
conditions. It has been observed, however, that there is a very close 
relationship between the precipitation and the loss in vitality in seeds; 
that is to say, in a measure the loss in vitalit}" is directly proportional 
to the amount of rainfall. This deterioration is more apparent as the 



OATTSES OE^ LORSEM TN VITALITY. 



23 



toin})or;iture iiicreiiscs, hut tlic injiii'v (luc to the iucrcast' in tcinpcM'ji- 
tiirc is (l('])(>ii(lont on the amount of moisture pi"oscnt. 

The following- table lias been compiled in order to show the ratio 
between the loss in vitality and the precipitation and temperature. 
'rh(> loss in \italitv. as o-iven in the second c(dumu of Table Vll, rep- 
resents the average losses in percentages, calculated from the results 
of the o(>rmination tests of the 13 dili'erent samples of seeds, as shown 
in Ta])le II. " 

The third column shows the annual precii)itation in inches. The 
annual precipitation has been taken, ])ecaust^ in st)nu> instances heavy 
rainfalls occurred just previous to the time that the seeds were put 
into storage. Then, too, the annual precipitation furnishes more accu- 
rat(^ data for a basis of comparison. The mean temperatures, as given 
in column 4, avo not the mean annual temperatures, but the averages 
covering the time during which the seeds were stored. The mean 
annual temperatures were not taken, chiefly for the reason that the 
critical period, in so far as tempiM'ature is concerned, is during the 
summer months. 

Table VII. — Jinlio hctireeii vit((lifi/, jir^Tip'iloMoii, ami fciiipiTidure. '' 



P'laoc^ ■wlioro seeds \veri> stored. 



Mobile, Ala 

Baton Rouge, La. 
Durham, N. IF . . . 

Auburn, Ala 

Lake City, Fla 

Wagoner, Ind. T. 
Ann Arbor, Mieh 



Average 
loss in vi- 
tality of 
thelHdif- 
feren I sam- 
ples of 
seeds. 



IT Clltf. 

71. '.IS 
ll.3<t 
39. fiS 
:!:?. 91 
29. as 

•JS.-ll 



Annual 

I>recipita- 

tion. 



Lirlifs. 
91. IS 
0(1. ;'," 
IS. 20 
(V2. CI 
■19. 7(; 
■12. 10 
2S. .5S 



Temperature. 



Maximum 
Fahr. 



Ihyrees. 
71.4 
72. 2 
.52. ;? 
(U. 4 
73.3 
(37. 1 
49.12 



Diyri 



90. 
9S. 
9S. 
9S. 
103.0 
107. 
9S. 



"These see<ls were seut <jiiI in l'"el>niM ly, 190(-), and were returned tii llie Ixilauiial l;d)()ratory and 
tested in October aud Noxcinber, 1900. The average time that the seeds were kept at the various 
places was 2.''v2 days. 

''Tlie results of the Sail Jtian tests have Iieeii (iniitted from this talile because, as has been pi\'viously 
stated, all of the seeds were returneil from San .liiau on .luiie 20, 1900, when the lirst tests were made. 
The second series of tests was made in October, 1900. During the time intervening between the first 
and seconil tests the San .luan samples were kept in the botanical laboratory at the University of 
Michigan. 

According to the table tlie seeds kept at Mobile snft'ered the greatest loss in vitality. However, it i.s 
quite probable that the greatest loss would have been from the seeds stored at San .Juan had the time 
of storage been tli(> same for the two ])laccs, so that the results of the San Juan tests could have been 
included in the table. This conclusion is based on the following facts: Normally, the number of rainy 
days at San .Tnan far exceeds those at Mobile. In U»00 there were 211 days on wdiieh rain fell in otiu 
.luaii, while the records for Mobile show only 1 lO. Likewise tlie average temperature of the dew-point 
Tor San Juan was 71° F. and only .')9° F. for Mobile, which, when expressed in terms of al)solute 
moisture, gives S.240 and ,')..'>."i.5 grains of water ]>er cubic toot at the time of saturation. On the other 
hand, the relative humidity of Sail Juan was 7s..'i per cent, or slightly lower than that of Mobile, the 
latter having a relative humidity of SO..T |>er cent. However, the mean annual temperatures were 
77.i'i'^ and 71.4° F., respectively, hence a mc^aii ab.solute humiiiity of 7.099 grain.s of aqueous vajwr for 
San Juan and only G.71S grains per cubic foot for Mobile. 



24 



THE VITALITY AND GERMINATION OV SEEDS. 



From the foreooino- tubh^ it will be seen that precipitation is a factor 
of much greater iniportaiice than temperature. In order to show the 
real value which the amount of precipitation furnishes as a ])asis for 
judging- the length of time that seeds will retain their vitality when 
stored in localities having- a marked difference in the amount of rain- 
fall, the results set forth in the above table are ri'presented diagram- 
matically as follows: 

J^jj'rcl (if }irecij)it<ition (>it vitality. 



Place. 



PercentiiKe of loss in vitality. 



Inches of precipitation. 



jNro))ne 


71. 9S 


91. IS 




Baton Rouge 


41.39 


(iCi. 37' 


Durham 


■Ml r.s 


-18. 20 




Auburn 


:!3. yi 


f)2. 61 


Lake <^itv 


'29. 3.S 
•Js. -11 


49. 70 


Wagoner .' 


42. 40 


Ann Arbor 


2.52 

m 


2S. M 






iiKMiB^HaiBBan 



A discrepanc}' is very marked for Durham, N. IT., which may be 
partially explained by considering again the conditions under which 
the seeds were stored. It will be remembered that these samples of 
seeds were stored in a hall which opened directly into a chemical labora- 
tor}'. It is (piit(^ probable that the low percentages of germination 
were due to the injurious action of gases emanating fiom the labora- 
tory. Of these gases, ammonia pi'o]>ably played a very important part, 
as it is well known that seeds are very readily injured wIkmi subjected 
to the action of annnonia. 

It is to be understood that the above comparisons are somewhat 
indetinite. If the amount of rainfall were equally distributed through- 
out the year a definite ratio could, in all probability, be established; 
l)ut in the majority of places there are alternating wet and dry seasons, 
Avhich make such a comparison very difficult and unsatisfactory. Yet 
for ordinary considerations it is sufficient to say that seeds will retain 
tlieir vitality much l)etter in places having a small amount of rainfall. 
For more exact comparison other factors must be taken into account, 
especially the relative humidity, mean temperature, and temperature 
of the dew-point, which ultimately resolves itself into the absolute 
amount of moisture present in the atmosphere. 

EFFECT OF MOISTURE AND TEMPERATURE UPON VITALITY. 

From the foregoing ^experiments it is quite evident that moisture 
plays an important part in l)ringing al)out the premature death of 
seeds and that the detrimental action of moisture is more marked as 



EB^FEOT OF MOISTTTRE AND TEMPERATTTRE. 25 

(lie Icinpci'utiirc iiicrciiscs. Foriiici-iy the ^cinM-al consensus ot' opinion 
has hren to make this stateniont in the rcNcrso order that is, tluit 
teniporatun- exerts a very harmful action on seeds it' much moisture 
l)e present. For compairatively hiu-h temperatures the hitter statement 
Avoukl proha])ly suffice — at least it is not misleading-, and in a certain 
measure it is true; but at the lowest known temperatures, as well as 
at ordinary temperatures, moisture is the conti'oUini'- factor, and in 
order to he consistent it should likewise l)e so considered for higher 
temperatures — that is, within reasonable limits. 

That temperature is only of secondary importance is brought out in 
the results o])tained by a nmnber of investigators. It has been well 
esta)>lished ])y Sachs," llal)erlandt,'' Just,^ Krasau,'' Isidore-Pierre,*' 
flodin,-', Dixon, f^ and others that most seeds, if diy, ai'e capable of 
germination after being subjected to relatively high temperatures for 
periods of short duration. The maximum for most seeds is a tempera- 
ture of loo-' C. for one hour; but if the seeds contain comparatively 
large quantities of moisture they ure killed at nnich lower tempera- 
tures. It has been reported that lettuce seed \\\\\ lose its vitality in 
two weeks in some of the tropical climates where moisture is abundant. 
Dixon has shown that if lettuce seed be dry it will not all be killed 
until the temperatui'e has l)een raised to 11-1^ C. 

In case of low temperatures the factor of moisture is of less impor- 
tance, yet even under such conditions the moisture must not be exces- 
sive or the injury will be (piite apparent. But if seeds are well 
dried it can safel}' ])e said that they will not ))e killed as a result of 
short exposures to the lowest temperatures which have thus far been 
produced. Our knowledge of the resistance of seeds to extremel}- 
low temperatures is based on the experiments of Edwards and Colin, ^' 
Wartmann,' 0. De C'andoUe and rictet,'' Dew\ar and McKendrick,^ 
Pictet,'^ C De Candolle,'" Brown and Escombe," Selby," and Thiselton- 

"Ilandlmeh d. Exp. Phys. d. Pflunzen, Txnpzig, 18(35, p. (>(>. 

'' Ptian/.fnl)au I, 1875, pji. lOK-llT; Abs. in Bot. .TiUire.sljr., 1875, p. 777. 

<'B(>t. Zeit., IVA, .lallr<,^ 1875, ]^. 52; Cohii's Boitriiffe zur Biol. <lcr Pflanzen, 1877, 
2: .SI 1-348. 

'/.Sit/Aingi^br. d. Wiener Akad. d. Wiss., 1873, 48: 195-208. 1. Abth. 

'Ann. Agron., 1876, 2: 177-181; Abs. in Bot. Jahrcsbr., 187(5, lb Abth., 4: 880. 

./"Compt. Rend., 1899, 129: 893-894. 

f/Natnre, 1901, 64: 256-257; notes from tlie I'.otanical Sehool of Trinity ColU'pre, 
Du1)lin, Angust, 1902, pp. 176-186. 

/'Ann. sci. nat. bot., ser. 2, 1834, 1: 257-270. 

'Arch. d. sci. phy.s. etnat., Geneve, 18(50, 8: 277-279; il)i(l., srr. :!, 1881, 5: ;:40-344. 

./Ibid., ser. 3, 1879, 2: 629-(332; i))i<l., ser. 3, 1884, 11: 32.5-:!27. 

^■Proo. Roy. Inst., 1892, 12: (W9. 

I Arch. (L sci. i)hys. etnat., Geneve, ser. 4, 1893, 30: 29.3-314. 

"' Ibid., ser. 4, 1895, 33: 497-512. 

"Proe. Roy. Soc., 1897-8, 62: 1(50-165. 

f'Bul. Torr. Bot. Glnh., 1901, 28: 67-5-679. 



26 THE VITALITY AND GERMINATION OF SEEDS. 

Dyer." In t\\v experiments of the la.st-named inve.stigator seeds were 
subjected to the temperature of li([uid hydroi^'en ( — 250 to — 252*^0.) 
for six hours, and when tested for vitality the trermination was perfect 
and complete. '' 

Much more might be said on the efiect of high and low temperatures 
on vitalit} \ But for the commercial handling of seeds the extremes 
of temperature are of secondary importance and need not be further 
discussed at this time. In the present work the purpose has ])een to 
show the effect of moisture on the vitality of seeds when subjected to 
such temperatures as are usually met with in the storing of seeds. 

SEEDS PACKED IN ICE. 

On February *s 1900, samples of each of thirteen kinds of seed 
were put up in duplicate, I)oth in manila coin envelopes and in small 
bottles. The bottles were closed with carefully selected cork stoppers. 
These two sets of duplicate samples were then divided into two lots. 
Each lot contained one of each of the packages and one of each of the 
bottles of seeds. The samples thus prepared were carefully packed 
with excelsior in wooden boxes, the boxes being then wrapped with 
heavy manila papei-. In one of the boxes was also placed a Sixes' 
self-registering thermometer, so that the minimum temperature could 
be ascertained. 

These boxes were stored in a large ice house near Ann Arbor, being 
securely packed in with the ice at the time the house was being filled. 
The first box was taken out with the ice on June 12, 1900, after a lapse 
of 126 days. The thermometer in this box registered a mininumi of 
— 3.6° C. It is safe to assume that this temperature was uniform, at 
least up to within a few da3^s of the time when the seeds were taken 
out. Unfortunately, absence from the univ^ersity at this particular 
time delayed an examination of the seeds until June 20. During the 
eight intervening days the box of seeds was kept in the laboratory 
and there many of the seeds in the packages molded, so that they were 
unfit for germination tests. In fact, the results of the tests from the 
packages are of little value within themselves; but in comparison with 
the ^'italit3^ tests of the seeds kept in the bottles some important facts 
are brought out, and it has been deemed advisable to tabulate these 
results with those of the second series. 

The second box of seeds was packed approximately in the center of 
a large ice house (100 by 60 by 20 feet) and was taken out wdth the 
ice on Jul}^ 21, 1900, after having been 167 days in (;old storage. The 

«Proc. Roy. Soc, 1899, 65: 361-868. 

'> Bmssiai aJha (oily), PIsidii sativum (nitrogenons), ('itCiirJ>il<i pejx) (oily), Trlticniii 
sat i nun (farinaceous), and Ilordemn ndgare (farinaceous). 



EFFECT OF MOISTURE AND TEMPERATURE. 



27 



l)C).\ was bronoht directly (o tlio hi])orat(>rv aiKl tlie seeds wei'(> exam- 
ined at once. Tliost'. contained in the paper })acka<4-es had a])sorl»ed a 
c()nsideral)le quantity of moisture and were much softened. In all of 
the packages except those containing- the onion and watermelon seeds 
some mold had developed; but in the seeds us(>d for the germination 
tests care was taken to avoid using those that showed any trace of 
a mycelium, there))}' reducing the injury due to fimgous growth to a 
minimum, even though sub.seqnent experiments have shown that such 
injury is practically negligible. 

An interesting point concerning the germination of some of the 
seeds at this low temperature may be stated in this connection. Eight 
of the peas, or 4 per cent, had already germinated, the radicles vary- 
ing in length from 1 to 2.5 cm,, thus corro))o rating Uloth's results in 
germinating peas at or slightly beloAV the temperature of melting ice.^' 

Tablk VIII. — Tlif ritalily of seeds kept in an ice Jtouse ineiiveloj^es (iiid holl/es, ami like- 
leise the vHnliti/ of the controls. 





First test 


after li 


G days. 




Second test, after 167 daj- 






(iermination. 


Differ- 
ence be- 
tween 
envel- 
ope and 
control 
sam- 
ples. 


Differ- 
ence be- 
tween 
envel- 
ope and 
bottled 
sam- 
ples. 


Germination. 


Differ- 
ence be- 
tween 
envel- 
ope and 
control 
sam- 
ples. 


Differ- 
ence be- 
tween 
envel- 
ope and 
bottled 
sam- 
ples. 


Kind of seed. 


Con- 
trol. 


Envel- 
ope. 


Bottlc. 


Con- 
trol. 


Envel- 
oi.e. 


Bottle. 


Corn ".\" 


l><r <i. 
9li. 
90. 
9.'). 
9;!. .5 
8,H. ,■> 
79. .'■■p 
92. 
100.0 
.")2. T) 
71.0 

'..S. 
.SO. 


Prr el. 
ltd. 
(;o. 
92. r> 

S9.0 

5.0 

73. 
90.0 


]'rr ft. 
91. 
90. 
90. 5 
94.0 
81 5 


Pit ct. 

110. 

30.0 

2. 5 

4.5 


Pa- ct. 

.58. 

30. 

4.0 

.5.0 


Prr (i. 
92. 
92. 

95. 
92. 
80. 5 
73.5 
94.7 

100. 
.52. 
.54. 

96. 5 
100.0 

81.5 


I'rr rt. 
H\. 
74.0 
94. 5 
90. 
74.0 
.52.0 
90. 
0.0 

11.0 
.51.5 
'.)G. 
GG. 


Prr ct. 
9G. 

94. 

95. 
94. 
89. 

96. 
98. 
G5. 5 
68. 5 
96.0 
100. 
71.0 


P(r cl. 
6. 

IS.O 

0.5 

2.0 

6. 5 

21.5 

4.7 

100.0 

49. 5 

43.0 

45. 

4.0 

15.5 


I'cr cl. 
10. 


Corn " B " 


20. 


Onion 


0.5 
4.0 


Radish 


15. 


Carrot 


80.0 
88. 

ia).o 

05.5 
"10.5 






2)i. 5 


I'ea 






G.O 


Bean 






98.0 


I'nnsy 

Phlox 


47. 5 


GO. 5 


G3.0 


Tomato 


93. 5 

100.0 

m. 


22. 5 
8.0 


20. 5 
10.0 


44.5 


Waternielon 

Lettuce 


4.0 
.5.0 










Average 


«7.3 


03. 


87.9 


25. 


27.7 


84.9 


62. 1 


87. G 


24.3 


27.0 



"In making np the averages the result of the germination of the phlox was omitted because a sub- 
sequent examination showed that the bottle containing this sample of seed was broken at the bottom, 
thus admitting sufficient moist\ire to destroy vitality, as is borne out liy the second test. 

The above table shows, as previously stated, that the results of the 
tirst tests are incomplete and not very satisfactory, owing to the fact 
that the germination tests were imavoidabl}^ dehu'ed for eight da3^s 
after the seeds were taken from the ice house; but with the second set 



" Flora, 1875, pj). 2()6-268. 



28 THE VITALITY AND GERMINATION OF SEEDS. 

of s;rm})l('s (lie counts for tlic vitality tests wore bei^'un within an liour 
from the time the seeds were removed from the ice house. Thus, the 
conclusions for these experiments must ])e drawn chiefly from the sec- 
ond series of tests. However, comparisons will be made with the 
first wdierc such seem justitiable. 

It will at once be seen that the seeds which were in paper packag-es 
gave a much lower percentage of germination than either the control 
samples or those kept in ))ottles. The average germination of the 
controls was S4.9 per cent, and the averag'e germination of the seeds 
kept in bottles was 87.6 per cent, whil(> only ()2.1 percent of the seeds 
kept in paper packages germinated. This is equivalent to a loss in 
vitality of 24.3 and 27 per cent, respectivel}', as compared w^ith the 
vitality of the control samples and the samples from the l)ottles. The 
results of the first tests are practically the same, save that the difi'er- 
ences between the control and the Ijottle samples are less marked. In 
the second case the average vitality of the seeds kept in envelopes was 
nuich reduced l)y the complete failure to germinate in the case of the 
beans, which are most susceptible to the deleterious action of moisture 
at the given low temperature. 

One of the most important points brought out by these experiments 
is the result obtained wnth onion, cabbage, and watermelon seeds. In 
both the first and the second tests the g-ermination varied but little 
throughout. Howev(n-, in all cases the seeds in the paper packages 
were slightly injured by the action of the moisture. This factor is of 
much importance, especially in the case of the onion seed, which, 
when k(^pt in a moist atmosphere at normal temperatures, soon loses 
its vitality, but when maintained at temperatures slightly l)elow 
freezing it becomes very resistant to the action of moisture. The 
beans, on the other hand, were all killed, although they are ordinarily 
much more hardy than onion seed. It is quite probable, however, 
that the death of the beans may be attributed to the reduction in tem- 
perature. Containing as they do large cpiantities of starch, they 
a])sor}) mor(^ water than less starchy or more oily seeds. This factor, 
together with the large embryo, renders them much more susceptible 
to the injurious action of freezing temperatures. 

Another important feature brought out by these experiments was 
the better germination of the seeds which had ])een stored in bottles 
in the ice house. The average germination of these samples was 2.7 
per cent higher than that of the control. In a measure this may be 
included within the limits of variation; but when it is considered that 
all of the bottle samples except the ])eans, tomato, and lettuce showed a 
vitality equal to or greater than the control, it can hardly be considered 
as a normal \'ariation, especially since only the lettuce gave an}^ marked 
variation in favor of the control. Likewise, the average percentages 



EFFECT OF MOISTURE AND TEMPERATURE. 29 

of the iir.st series of tests show ii slight iiicreuse in fa vol' of the seeds 
kept in the l)ottles, thou^'h the increase is not so well niar-ked and is 
less uniform than in those of the second series. 

Aside from the tinal g-ermination there is still another factor that 
must ])e taken into consideration as bearing evidence of the advantage 
oi keeping seeds at low temperatures, provided that they are kept dry. 
All of the samples that were stored in the ice house in bottles showed 
a marked acceleration in germination. It is (piite evitlent that the res- 
piratory activities and accompan3'ing chemical transformations were 
much reduced ]\y the reduction in temperature, and the A'ital energy was 
thus conserved; ))ut when the conditions were favorable for germination 
the greater amount of reserve energy in these seeds ga\e rise to a more 
vigorous activity within the cells and a correspondino' acceleration in 
germination. 

Numerous other experiments showing the effect of moisture on ttie 
vitality of seeds were made. In contrast to those just given, the 
injurious action of moisture at higher t(Mnperatures, yet temperatures 
well within the limits of those ordinaril}' met with in the handling of 
seeds, will be next considered. 

EFFECT OF IMOISTURE OX VITALITY AT HKiHEIi TEIMl'EUATUKES. 

This set of experiments was undertaken particularly to furnish con- 
ditions somewhat similai' to those existing in the States bordering on 
the Gulf of Mexico, or, in fact, all places having a relatively high 
degree of humidit}" and a temperature ranging from 80-" to 37^ C. 
(86" to 1)8.6-" F.) during the summer months. In ordei- to secure the 
desired degrees of temperature two incubators were utilized, one being- 
maintained at a temperature varying from 80 to 32 C, the other 
from 36"^ to 37-' C. The thermo-regulators were so adjusted as to 
admit of a possible variation of nearly two degrees in each case. 

Beans, cabbage, carrot, lettuce, and onion were used for these tests. 
In each of the incu])ators the seeds were subjected to four diU'erent 
methods of treatment: 1. In a moist atmosphere, in triM- coinimuiica- 
tion with the outside air. 2. In a moist atmos])h(M(\ but not in con- 
tact with fresh air, the seeds being in. sealed ])ottles of 250 cc. capacit3\ 

3. In a dry atmosphere, in free communication with tho outside air. 

4. Air-dried seeds in sealed l)ottles. 

In order to obtain the conditions requisite for the lirst method of 
treatment, an apparatus was used as shown in tigure 1. The seeds were 
put up in small packages and then placed in a 25<) cc. bottle. The bottle 
containing the packages of seeds was placed withi^n a specimen jar 
which was partially tilled with Avater. This jar was th(Mi closed with 
a hirge cork stopper which carried two glass tu])es, (^acli of I cm. bore. 
These tubes extended 25 cm. above the top of the jar and out through 



30 



THE VITALITY AND GEKMINATION OF SEEDS. 



^^ 



the opening in the top of the incubiitor. The pi'iniary object of the 
tubes was to prevent an}' water vapor from escaping within the incu- 
bator and thereby doing damage to the seeds that were to be kept dry 

in the same incubator. For the same reason 
the cork in the jar was well coated with paraf- 
fin. Approximately the same volume of water 
was maintained in the jar throughout the ex- 
periment, more water being added through 
tube a, as occasion demanded, to replace the 
loss by evaporation. The chief advantage in 
having two tubes was the comparative ease 
with which the air within could be displaced 
})y a fresh supply by forcing a current of fresh 
air through one or the other of the tubes. 

Two such preparations were made, one being 
left in the oven maintained at a temperature 
varying from 30 ' to 32^ 
C. , the other in the oven 
maintained at a tempera 
ture varying from SB-' 
to 37-' C. In both cases 
the })ottles contained 
ti\'e packages of each of 
the five samples of seed, 
tiuis making provisions 
for testing at ditierent 
intervals. 

In order to suppl}' the 
conditions for the second 
method of treatment, 
similar packages from the same samples of seeds 
were put into 8-ounce bottles, which were then 
kept for five days in a moist chamber. The in- 
crease in weight due to the absorption of water 
within the five days was as follows: Beans, 3.03 
per cent; cabbage, 8.09 per cent; carrot, 8.26 per 
cent; lettuce, 7.45 per cent, and onion 8.43 per 
cent. This increase, with the water already 
present in. the air-dried seeds, gave a water con- 
tent of 13.23 per cent for the beans, 13.99 per 
cent for the cabbage, 13.60 per cent for the carrot, 
12.45 per cent for the lettuce, and 14.84 per cent 
for the onion. 

Th(^ bottles were then corked and sealed with paraffin, Ijut were so 




Fig. 1.— Apparatus used to (U-- 
tenninc the effect of moisture 
and temperature on tlie vitality 
of seeds in communication witli 
free air. 




Fig. 2. — Apparatus used to 
determine the effect of mois- 
ture and temperature on the 
vitality of seeds not in com- 
munication with free air. 



EFFECT OF MOISTMKE AND TEMrEKATHRE. 31 

('oiisti-iictcd thai the i'('l:iti\(' luiiiiiditv of (lie inclosed air could ))0. 
iiici'casod wi(liou( the axhiiissiou ol' more fi'(M' air. The detailed cou- 
structioM of this a])|)aratus is shown in lio-. 2." 

The seeds cont inned (o ahsorh inoistui'e to a Hunted e.xlcul. 1 u order 
that the iuidosed aii" unoht he uiaintaiued at ai)|)roxiuiat(d_v the same 
(Ictjfree of saturation, a ci'U(U^ hy^roscopcMvas attacluMl ou th(> inside of 
each l)ottl(\ These h y_nTosc<)})es were made from awiis of S/Jjxr 
C(t2>'ll(il(i L. , th(> tip of th(> awns heino- i-(Mnoved and a short piece of lino 
co])])er wire us(h1 as an indicator. These hyoi-osco])es wiM'e sus])end(Ml 
from the under side of the cork, as shown at //, and i>\ \\\v side of eacii 
was sus))ende(l a tine fihei' of silk, which, beini;' carried around l»\- the 
indicutor, i'ecord(>d th(> numbcM- of turns made by tiie awn. 

V\\y' such })i'e])ai"ations wei'c made for eacli of tJie two sets, so as to 
furnish seeds foi- a stM'ies of tests. One set was ke})t at a tem])(M'ature 
of 30'^ to 82 (I, the other at 80 to 37 C. The ^i^x^d fi-om one of tiic 
bottles, at each of the t(MU])eratures, was wei,i;"he(l after eiy'hty-oiK^ 
days, at tlu^ time the o(Miuinatiou tests were made. These wcd^hin^'s 
showed that at the h)wer t,emp(»ratures the a\<>ra_n'e increase in w(Moht 
for all the seeds was S.() per cent, and at th(> higher tempei-atnres. (I.I) 
per cent. The increase in the case of the beans was (|uite mai'ked at 
this time, bein<i- !;!.;'> per cent for those maintained at a temj)eratui"c 
ninoing- from 30 to 3:^ C, and !>.S piM- c(Mit for those maintaincMl at 
30 to 37 ('. 

The third set of conditions consisted siiujdy of i)a('kayes of the air- 
dried seeds ke])t in ojxmi boxes in each of the incubators. This series 
of tests was made especially for the [)uri)ose of det-ernuninti' the etl'ect 
of dry heat on the \ itality of schkIs when maintained at the tempera- 
tures above o-iven for some consid(M'able time. 

Foi- the foui'th sei-ies small packag-es of the seeds were put into 
U-ounce ])ottles, which werc^ then corked and sealed with ]iarallin. Fi\c 
of these bottles were k(^pt in each of the ovcmis and y(>rmination tests 
were made at irrea'ular intervals. The results of these tests fu rtush a 



« The wiile-mouth l)<)ltle (/*) contiiins the paclvages of seed (.s-)- Tlnoiifj;!! an <ii)cn- 
ing ill tlie cork iw iiiHerted a short piece of soft <j;lass tu])iiijj;, iH'irij,' lirsl fused at the 
k)wer end and liavinjj a slight constriction drawn at c At a distance of I cm. 
above tiie constriction is ))lown a small opening, as shown at o. A short piece of 
heavy rnbher tuliing (/), cemented on a piece of heavy brass wire (//), serves as a 
stopper. 'I'his stojiper, whicii nnist lit closely within (lu^ glass (nhc, is operated by 
means of the heavy wire. When drawn np, the water- in the tube nia>' give off 
a(iueous \apor, which can escaj)e through the small opening (o) into the bottle. 
When suflicient moisture is present the supply is shut nff by pushing the stopper 
down linnly against the constriction. The .stopper must be well coated with va.s- 
eline to prevent its sticking to the sides of the glass tul)e. To make the apparatus 
more secure against the entrance of fresh air, a second piece of i-nbber tubing (r) 
is j)lace(l in Ww, upju'r jiart of thc^ glass tube, the to|i of w hich is then tilled with oil. 



32 



THE VITALITY AND GERMINATION OF SEEDS. 



basis for compariiiu- the relative merits of keeping" seeds in open vessels 
an<l in sealed }>ottles. 

Table IX will show the eli'ect of the various methods of treatment 
on the vitalit}' of the seeds. 

Tai'.le IX. — ]'ilaliri/ of seeds irlu-ii. siihjecled lo Ihe dctioii of (i dnj aud a moid ahnosplierr^ 
both irlieii e.eposed to free air and irjien confined in (/hiss Injttles^ at reliitirehj high 
temperatures. « 



Kind of seed. 



Beau.. 
Do 
Do 
Do 



Begin- 
iiiiiK of 
experi- 
ment. 



End of 

e.xperi- 

mentand 

date of I 

tion tusts.i 



Dura- 
tion 
of ex- 



Mar. 
...do. 
. . .do . 
...do. 



Cabbage . . 
Do ... . 
Do . . . . 
Do . . . . 

Carrot 

Do ... . 
Do ... . 
Do ... . 

Lettuce . . . 
Do ... . 
Do . . . . 
Do . . . . 

Onion 

Do . . . . 
Do ... . 
Do ... . 



...do. 
...do. 
...do. 
...do. 

...do. 
...do. 
...do. 
...do. 

...do. 
...do. 
...do. 
...do. 

...do. 
...do. 
...do. 
...do. 



Apr. 

Ma,y 
May 
July 

Apr. 
May 
May 
July 

Apr. 
May 
May 
July 

Apr. 
May 

May 
July 

Apr. 
May 
May 
July 



Daija. 
31 
(19 
M 
110 

\M 
(19 



Vitality of seeds when 
kept in a moist at- 
mosphere. 



In open bot- 
i\e9., at tem- 
peratures 
varying 
from — 



In sealed 
bottles, at 

tempera- 
tures vary- 
ing from — 



30° to 36° to'30° to 36° to 
32°. 37°. 1 82°. 37°. 





.SI 




110 




31 


12 


69 


21 


SI 


22 


MO 




31 


12 


69 


2-1 


81 


22 


140 




31 


12 


69 


24 


SI 


22 


140 



P. ct. 
100.0 
97. 5 
94. 
2.3 

S7.8 

71.6 

SO.O 

0.0 

83. h 

69. T) 

■!8. 

0.5 

92. 5 

38. 

55. 5 

0.0 

95. 5 

68. 

59. 5 

0.0 



P. rt. 

100.0 

0.0 



90. 5 
0.0 



77.5 
0.0 



90. 5 
0.0 



89.0 
0.0 



P. rt. 

78.0 

75.0 

0.0 

0.0 

73.0 

30.0 

1.0 

0.0 

5-1. 5 



0.5 

78. 

44. 5 

1.0 

1.5 

61. 5 
2.5 
0.0 
0.0 



30° to 36° to 30° to 36° to 
32°. 37°. 32°. 37°. 



P. ct. 

44.0 
0.0 
0.0 
0.0 

72. 5 
0.0 
0.0 
0.0 

29. 5 
0.5 
0.0 
0.0 

.58. 
2.0 
0.0 
0.0 

•15.0 

-0.0 

0.0 

0.0 



Vitality of seeds when 
kei)t in a dry atmos- 
phere. 



In open 
boxes, at 
tempera- 
lures vary- 
ing from — 



In sealed 
bottles, at 

tempera- 
tures vary- 
ing from — 



P. rt. 

86. 
100.0 

98. 
100.0 

86. 5 
67. 5 
89. 
81.0 

84.5 
82. 
11.5 
81.0 

91.0 
42. 
65. 
82. 

95. 5 
97.0 
95. 5 
90.0 



P. rt. 
84. 
90. 
90. 
9-1. 

Sl.O 

87. 9 
92. 
83.0 

88. 
8,5. 
50.0 
81.2 

86. 5 
38. 5 
58. 5 
87.0 

93. 
95.0 
94.0 
92. 



P. rt. 
98. 
92. 5 
98.0 
98. 

83. 5 
79. 
92. 5 

88. 5 

89. 5 
83. 5 
50. 

78. 5 

91.5 
38.5 
62. 5 
81.5 

96.0 
97.5 
99. 
97.5 



(ier- 
mina- 
tion 
of 
con- 
trol 
sam- 
ples. 



P. rt. 
98. 
95. 
100.0 
96. 

86. 9 
78.5 
92. 
86.7 

89.0 
82. 5 
48. 
83.1 

90. 
51.5 
67.0 
88.0 

97. 5 
93.0 
95.0 
94.7 



P. rt. 
94.0 

98. 7 

98. 

99. 4 

91.0 
S3.0 
92. 5 

93. 1 

92. 5 
78.0 
61.5 
S3. 1 

90. 
31.5 
53. 5 
79. 9 

96.0 
98. 5 
96. 5 
95. 4 



<i K study of the table will show that the lettuce and carrot seed germinateil very poorly at the end 
of 69 and 81 days. This, however, was not due to any inherent iiuality of the seed, but to an excess- 
ive temperature at tlie time the tests were made. Both of tlu-se see<1s reipiiri' a couiiiaratively low 
temperature for their successful germination, lettuce germinatin.g best at 20° C, and carrot at an 
alternating temperature of from 20° to 30° C. 

The amount of moisture absorbed oi" expelled under the different 
methods of treatment has an important bearing on the duration of 
vitality and will be considered briefly at this time. Only the general 
results will be disc'sscd in this connection, inasmuch as later experi- 
ments, carried out in a similar manner, show the detailed results to 
much better ad\'antage. Nevertheless, it requires onl}' a glance at 
the above table to show the marked difference in the germintitive 
power of seeds which have been stored in moist and in dry conditions. 
The seeds which were exposed in a moist atmosphere to the higher 



EFFECT OF MOISTURE AND TEMPEKATIIRE. 83 

teinpcraturcs (;i»; to H7" C.) were killed imicli earlier than those 
.subjected to the moist atiiios})here at the lower temperatures —30"^ to 
32" C — ill })otii tlie open and the closed bottles. 

A weighing" at the end of Hi days showed that the average increase 
in weight of the seeds kci)t in the open, moist chamber, due to tiic 
absorption of moisture, was (J per cent at a tempei'ature of 30 to 
32 C, and 5 i)er cent at a temperature of 3()^ to 37 C. For the 
seeds kept in the oven, maintained at the temperature of 30-' to 32 C, 
another weighing was made at the end of 134 days, at which time the 
a\erage increase in the water content had risen to S.dT per cent. 
Unfortunately tlu» seeds from the second o\'en, maintained at the 
higher temperature, had become badly molded in »)!) days, so that only 
the one weighing was made. 

Vitality tests made at this time, (>1> days, showed that all of the 
seeds from the open, moist chamber, at the higher temperatures, had 
been previously killed as a result of the drastic treatment; conse- 
quently no future germination tests were made. Those maintained at 
the lower temperatures were almost entirely free from mold at the 
expiration of the experiment, only an occasional seed showing any 
trace of fungous growth. Nevertheless, germination tests showed 
that the vitality had been destroyed in the ca))l)age, lettuce, and onion. 
Beans and carrot were most resistant, the former having germinated 
2.3 ])er cent and the latter 0.5 per cent. All of the seeds had become 
very much softened. The beans and the lettuce had changed very 
materially in color, the beans (Early Kidney Wax Six Weeks) having 
become nmch darker and the lettuce (Black-Seeded Simpson) almost a 
hnnon color. 

With the seeds constituting the second series, i. e., ni a moist Kfnios- 
ji/i, r< Imt In scaled hottleK:^ the injury was much more severe. Here, as 
with the open chambers, the seeds subjected to the higher temperatures 
were killed lirst, even though the amount of moisture actually absorlu'd 
was less, as was also true with the other series. A weighing made- at 
the end of SI days gave an increase of 8.0 per cent for those from the 
oven maintaijied at a temperature of 30" to 32" C. , and 0.3 per cent at the 
higher temperature. Likewise, in this series, the seeds had become 
very much softened and a very disagreeable odor had developed as a 
i-esult of the putrefaction of their nitrogenous constituents. A close 
examination made at the end of 81 days revealed slight traces of fun- 
gous growth, but then> is no reason to l)elieve that these played any 
part in the destruction of vitalitv. However, in making counts for 
germination tests all molded seeds were carefully discarded. 

The results of the germination tests showed that the vitality of the 
seeds kept at the lower temperatures had ])een practically destroyed 
at this time. The ]>eans and onions failetl to germinate, while the 
25U37— No. 58—04 o 



34 THP] VITALITY AND GERMINATION OF WEEDS. 

ciib]);iji;o, carrot, and k'ttucc »^erniinate(l only 1, 2.5, antl i per cent, 
respectively. 

During" the succeeding (JO days nuicli mold liatl developed, and at 
the expiration of the experiment, 140 days, only the carrot and the 
lettuce gave any indications of vitality. It is especially interesting to 
note with what rapidity the deterioration took place between the sixty- 
ninth and the eighty-first days, showing that Avhcn vitality reaches a 
certain point in its decline there follows a comparatively sudden 
death. This same fact is also shown in the case of those seeds in this 
same series kept at the highei' temperature. After 31 days' treatment 
they all failed to germinate, except 0.5 per cent in carrot and '•2 per 
cent in lettuce seeds. 

In the two series of experiments just considered there was an increase 
in water content as a result of the humidity of the air in which the 
seeds were kept. But the third series, (/j)cn and dry^ presents (juite 
another factor. A weighing made at the end of 30 days showed that 
there had ])een an average loss of 2.5 per cent for the lower tempera- 
tures and 3.5 per cent for higher temperatures. After this time the 
weight remained nearl}^ constant. Subsequent experiments, which 
will be considered later, also show that the water capal)le of being 
expelled at any given atmospheric temperature is driven oil in a coni- 
paratively short time. In case of seeds this condition is practically 
completed in eight or ten days when maintained at temperatures as 
above given. This extra drying of the seed causes a greater contrac- 
tion of the seed coats, and in a number of cases a corresponding 
retardation in the rapidity with which germination takes place. The 
retardation in the germinative activity is dependent on the increased 
difficulty with which the seeds absorb water, and in man}^ cases has an 
important bearing on the vitality tests. 

The fourth and last series, in which the air-dried seeds were sealed 
in bottles and subjected to the temperatui'es at which the two ovens 
were maintained, gave still another very different set of conditions. 
Here there Avas also an increase in weight, due probably to some 
process of oxidation, but the increase was very slight. The average 
increase from those kept at either of the temperatures was less than 
one-half of one per cent. 

Seeds, if Avell matured and thoroughly air-dried, are not injured 
when kept at temperatures below 37° C, whether they be kept in free 
communication with fresh air, or in sealed l)ottles, or tubes. In the 
experiments under discussion the average percentage of germination 
was slightly higher in the case of the seeds which had been stored in 
the sealed bottles. The mean percentage of germination for the seeds 
which had ])een exposed to the open air at a temperature of 30° to 
32° C. was 83.05 per cent. Those from the sealed bottles kept at the 
same temperature germinated S4.82 per cent. At the higher temper- 
atures — 30 -' to 37'^ C. — the mean germination of the seeds from the open 



EFFECT OF MOISTURE AND TEMPER ATTHiE. .35 

and the closed l)ottle.s was S2.()S and 85. (i2 percent, respectively. The 
control sample germinated 85.45 per cent. That 87"^ C is about the 
maximum temperature at which air-dried seeds can be stored without 
injury is shown by the followini^' experiments. 

Preparations similar to those alwvo mentioned were used, and after 
l)eing" sul)jected to a temperature of 37"- C. for 2ll> days, there Avas no 
appreciable loss in vitality, except the deterioration of 4 per cent in 
the case of the cabbage seed that was kept in an o])en bottle, and ij.'S 
per cent in the seed from a closed ])ottIc." But by increasing- the tem- 
perature, durino- an additional period of »)8 days, from 37^ C. to a 
maxinuuu of 44'-' C, the injury was nnich more marked, especially in 
the closed ])ottles. In the open bottles the vitality of thecal)bage was 
lowered from 5)1.3 per cent to 77 per cent, representing- a loss in vital- 
ity of 15. GO per cent. The onion seed fell from ;»5.7 per cent to 87 
per cent when kept in an open bottle, and to (51 per cent when kept in 
a closed bottle. The beans showed no apparent injury in eithtu- case, 
except that tli(\y ))ecame very dry; consequently there was a retarda- 
tion in o-ermination as a result of the slow al)sorption of water. 

The o-nniter loss in vitality of the seeds kept in the ])ottles was the 
direct result of the hi^-her humidity of the air immediately surroundino- 
the seed, and not l)ccause there was ;i deficiency' in the supply of fresh 
air, as migiit be readily assumed. In the open receptacles the tidditional 
amount of free water expelled, as a result of the increase in tempera- 
ture, was allowed to escape, while in the sealed bottles it only oave 
rise to a relatively moist atmosphere, and conseiiuently to a premature 
death of some of the seeds. If seeds are to be so confined, they should 
be previously dried at a temperature at which they are to be stored. 

All of these seeds had become very dry and brittle. The odor of 
the air confined within tlu' sealed bottles luid l)ecome very unpleasant; 
likewise there was a marked change in the color of the seed coats of 
the inclosed seeds. 

SUMMARY. 

Most seeds if kept dry are not injured by prolonged exposures to 
temperatures l)elow 37'-' C. (98.6'-' F.), it being inunaterial whether they 
are in open or in sealed bottles. 

If the temperature be increased above 37"^ C, vitality is seriously 
reduced. 

If seeds are kept in a moist atmosphere, a temperature even as high 
as 30" C (SG'^ F.) works uuich injury in a comparatively short period. 
The degree of injury rapidly increases as the temperature rises. 

Provided the degree of saturation is the same, the deleterious eti'ect 
of moisture is fully as great in open as in closed l)ottles. 



"Only cabbage, onion, and beans were used for this experiment, the carrot and 
the lettuce seed being omitted. 



36 THE VITALITY AND GERMINATION OF SEEDS. 

THE EFFECT OF DEFINITE QUANTITIES OF MOISTURE ON THE 
VITALITY OF SEEDS WHEN THEY ARE KEPT WITHIN CERTAIN 
KNOWN LIMITS OF TEMPERATURE. 

The results of the ex})erinient,s ju.st discussed furnish a fair criterion 
I)}' which to judge the vitaHty of seeds when inHuenced l)y tempera- 
ture' and moisture. It was still necessar}' to determine the effect of 
definite quantities of moistiu-e on the vitality of seeds when they are 
submitted to temperatures well within the limits of that which may 
be encountered in counnercial transactions. 

On Decem])er !!♦, 1900, preparations were made to determine these 
factors. Seeds of ca])bage, lettuce, onion, tomato, and peas were used 
for these experiments, which continued for TO or 72 days. All of this 
seed was of the harvest of 181)9 and had been in the laboratory during 
the eleven months immediately preceding the setting up of the experi- 
ments, being thus thoroughly air-dried. The amount of moisture 
present in the seeds at this time, as indicated by drying at 100'-' C, 
was as follows: Cabbage, 5.90 per cent; lettuce, 5 i)er cent; onion, 6.-11 
per cent; tomato, Ir.Tl per cent, and peas, 8.-1-1 per cent. 

The preparations were made as follows: 

[a) Air-dried seeds were placed in bottles of 125 cc. capacity. The 
})ottles were closed with cotton plugs in order to protect the seeds 
from dust while permitting a free circulation of air. This set served 
largel}^ as a check. 

{h) Air-dried seeds were carefully weighed and then ])ut into 125 cc. 
bottles, closed with firm corks, and sealed with paraffin. 

{(\ d, c, and /') These samples were also carefully weighed and 
sealed in bottles as I, but in the ditl'erent series of bottles there was 
first introduced 0.5, 1, 2, and 8 cc. of water which had been })reviously 
absor])ed ]»y small strips of lilter paper. 

{(/) The seeds constituting this series were first dried for 30 days at 
a temperature of from 80- to 82 C. and then put up in Iwttles which 
were sealed with paraffin. The loss in weight as a result of the dry- 
ing was as follows: Cab))age, 2.41 per cent; lettuce, 2.59 per cent; 
tomato, 2.71 per cent, and onion, 3.47 per cent, leaving a water con- 
tent of only 3.49 per cent, 2.41 per cent, 2 per cent, and 2.94 per cent, 
respectively. (Peas were not included in this series.) 

One of each of the al)ove preparations was then subjected to different 
degrees of temperature as folloAvs: 

(1) Outdoor conditions, protected from rain and snow, but freely 
subject to all changes in temperature and humidity. The temperature 
during the time of the experiment, Decem])er 19, 1900, to February 28, 
1901, varied from a iiiininumi of —21.(5'^ C. to a maxinuim of 8.9" C. 

(2) In a fruit c(41ar having a comparatively low and uniform 
temperature ranging from 10-^ to 18- C. 



EFFECT OF DEFINITE QUANTITIES OF MOISTURE. 87 

(;>) In the "dark room" of tho botanical laboratovv, which was 
quite dry and maintained at a temporaturo of 2<) to )i"2 C 

(4) In tho lierharium room on the fourth floor of the botanical labo- 
ratory. The air hero was very dry and tho mean tompei-ature about 
tho same as for No. 3, but with a much wider variation, roachino- at 
times a maximum of 30' and a minununu of 10 ' C 

(5) In an incubator maintained at 30'^ to 32' C. 
(0) In an incubator maintained at 37 to 40 C. 

It will be observed that all of tho preparations, except Nos. 1 and 4, 
were kept at temperatures which were quite uniform. The increase 
or decrease in the weight was determined at the expiration of To or 72 
days by again carofull}' weighing- the seed, after which germination 
tests were made. The results of the germination t(>sts and the gain or 
loss in weiiiht are o-iven in Ta))le X. 



38 



THE VITALITY AND TERMINATION OF REEDS. 



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EFFECT OF DEFINITE QUANTITIES OF MOISTURE. 



39 



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40 THE VITALITY AND GERMINATION OF 8EEDS, 

The t'oroo'oino' tablo, showino- the conditions under which the seeds 
were kept, has l)een made cjuite conipleto. Aside fi-oni the linal per- 
centa^'es of gerniination, the percentag'es of o-ei-niination after a defi- 
nite niunber of hours have likewise been given, the latter being better 
expressed as gerininative energy. The germinative energy, as has been 
previously stated, is an important factor in determining the potential 
energy of a seed. This is quite clearly shown in many of the germi- 
nation tests recorded in the above table. The preliminary resvdts show 
a marked contrast as a result of the ditferent kinds of treatment, while 
the tinal results reveal nothing more than the regular degree of varia- 
tion usually met with in testing seeds. Of the five species of seeds, the 
onion has yielded the most striking variations in the earlier stages of 
germination. Take, for example, No. 153.5, the sample that was kept 
in an open ))ottle in the fruit cellar. The moisture absorbed was suffi- 
ci(Mit to cause a chemical transformation, which injured the vitality of 
the seed and conse(iuently caused a retardation in germination. No. 
1539, the onion seed from the incul)ator maintained at a tempei-ature 
of 37-" to 40- C, germinated only 1(5.5 per cent in 77 hours, while 
the tinal percentage of germination was '.♦5.5 per cent. Onion seeds 
Nos. 153y and 1533 gei'minated in 77 hours 18.5 and 2.5 per cent 
respectively, while the tinal germination of the former was l>3.5 per 
c(Mit and of the latter iMI per cent. All of these tests gave Hnal per- 
(•(Mitages of germination somewhat highei' than the mean of the control 
sauiph^s. But the g(>rmination was consideral)ly retarded, the control 
samples having gei-minated 29.5 per cent dui'ing the first 77 hours. 
These retardations in germination nuist be due to a lowering of vitality, 
as a more careful study of the table will sliow, and not to any excessive 
drying that may have taken place dur-ing the time of treatment. 
Numerous other examples are to be found in the table, some even 
more striking than those mentioned, but it is not deemed necessary 
that the3^all be pointed out and discussed here. 

The table also shows the results of the ^•arious weighings made of all 
of the different samples which were kept in closed bottles. With but 
very few exceptions there was an increase in weight, which iiu'rease 
was qnite marked in all cases where free water was introduced. The aii"- 
dried seeds that were sealed in bottles without the introduction of free 
water all increased slightly in weight, with the exception of the peas, 
Avhich showed a slight decrease in weight. It has been ol)served that 
the absolute loss in the weight of the peas Avas slightly greater tlia!i 
the total gain in the four other samples of seed. This, however, is 
not of sufiicient uniformity throughout to fully justify the conclusion 
that cab1)age, lettuce, onion, and tomato seed have a greater affinity for 
wat(M- than peas, and that the formei- ro])bed the latter of a portion of 
their water content. Yi^t a portion of the increased weight of the 
cal>bage, lettuce, onion, and tomato seed is probably best accounted 



EFFECT OF DEFINITE (iUANTITIF:S OF MOISTURE. 41 

for in that way. On the other hand, it is quite pi-ol»al»h> tiiat a por- 
tion of the increase in wei<2,htwas due to the results of intraniolecuhir 
transformations and to the coexistent respiratory activities of the 
seed. The means of making- tliese determinations are far from eas3\ 
Van Tieghem and (J. Bonnier have shown" that seeds kept in sealed 
tubes in atmospheric air increased in weight during two years, but the 
increase a\ as xer} small. In their experiments the peas which were 
in sealed tubes increased ^ Jjr <>f their original weight. A corresponding 
sample kept in the open air increased .-V of its original weight. 

Nos. 1540 to 15-1-5 in Tabh> X show an increased weight in seeds 
when sealed in bottles for To days. These seeds were previously 
dried for 30 days at a temperature of P>0 to 32 ' C Disregarding the 
increase in weights as above given and the factors to which such 
increase may be attributed, it is (|uite evident that in all cas(\s where 
water was added the increase in weight was Auo chiefly to the absorp- 
tion of the water. The absolute increase was api)i'oximately the same 
as the weight of the watin* added. 

The amount of water absorbed by diU'eivMit seeds varies greatl}' 
under identical conditions, depending lai'geiy upon the nature of the 
seed coats and the composition of the see(l. The av(M'ag(> increase in 
weight of the seeds used in these ex})eriments was as follows: Onion, 
6.27 per cent; pea, 5.51 per cent; ca])bage, 1.12 ])ei-cent; lettuce, 3.1H) 
per cent; tomato, 3.1H» per cent. The loss in vitality of the corre- 
sponding samples was 2S, 12, 23.7, 18.5, and 14.7 per cent, respec- 
tively. The relationship here is quite (dose, the amount of water 
absorl)ed being roughly proportional to the loss in \itality. The 
penis, however, afford an exception to this general statement. But it 
nmst be rememl)ere(l that peas require a nuich lai'ger ]^(M-centage of 
moisture to start germination and are likewise capable of undtM-going 
much wider variations than the other secnls in (juestion. However, 
before a dt^finite ratio can \)e established between the absor})tion of 
water and the loss in vitality, many other factoi's nmst !)(> tak(Mi into 
consideration, such as the composition, water content, and duration of 
vitalit}' of the seed under natural conditions. 

Another interesting factor is shoAvn in No, 1540 of Tal)le X. These 
seeds were dried for 30 days at a temperature of 30 ' to 32' C'., after 
which they were kept in an o])en 1)ottle in the laboi-atory for 40 days. 
During the 30 days' drying th(^ cabbage lost 2.41 percent, lettuce 2.51) 
per cent, tomato 2.71 per cent, and the onion 3.47 pei- cent of moisture. 
These same seeds when exposed to the free air of the lal)oratory for 40 
da} s never regained their original Aveight, the incr(>ase being as follows: 
Cab])age, 0.6 per cent; lettuce, 0.58 per cent; tomato, 1.56 per cent; 
onion, 0.89 per cent. 'I'he average quantity of water expcdied was 2.79 



f'Bul. Soc. ])ot. France, 29: 25-29, 149-15;;, 1882. 



42 THK VITALITY AND riKRMINATTON OF SEEDS. 

per (-out in ?>() days, while tlio aver:io-o ineroaso in weight (luving-tho -iO 
da^^s was onij^ 0.91 per cent. These results show that if seeds are once 
carefully- and thoroughly dried, thej^ will remain so; that is, if kept in 
a eomparatiyel^y dry room. This is an important factor in theprcser- 
yation of vitality, as is ])orne out in the results of the germination 
tests. Later experiments were made with very similar results, and an 
analogous method of treatment promises to be of much value as a 
preliminary handling of seeds. It is not detinitely known to what this 
stronger vitality is due, whether it be simply to the etlect of the dr}'- 
ing or to some process of chemical transformation which makes the 
seeds more viable. These results are now" under consideration and will 
be reported at some future time. 

The table also shows in a very striking degree the decrease in the 
number of germinable seeds with an increase in the moisture and 
temperature. The amount of moisture absorbed l^y the seeds, with a 
limited amount present in the bottles, was inversely proportional to the 
temperature. At the higher temperatures the iliclosed aii- held a larger 
portion as water vapor; however, there wiis a greater deterioration in 
vitality. Where the seeds were kept outdoors at the low temperatures 
( — 21.0'' to 8.9° C.) of the winter months, no injury was apparent 
except where 3 cc. of water was added, and then only the onion seed 
was affected. This sample of seed had absorbed a quantity of water 
equal to 10.88 per cent of the original weight, whicli together with 
the original water content (6.4:1 per cent of the original sample) made 
17.88 per cent of moisture in the seed. Practically the same results 
were obtained with the seeds kept in a fruit cellar at a temperature of 
10° to 13- C. The samples of this series, in the open bottles, were 
also injured, as has been pointed out. With the samples that were 
stored in the dark room and in the herbarium room, the injury was 
more marked as a result of the higher tenqierature; but even here the 
seeds in the V)ottles which contained 0.5 cc. of free water deteriorated 
ver}' little. The injury was confined to the onion seed, which showed 
a slight retardation in germination. Where 1 cc, 2 cc, and 3 cc. of 
water were added, vitality in some instances was likewise remarkal)ly 
well preserv^ed. The lettuce, tomato, and peas gave no indications of 
any deterioration save in the bottles containing 3 cc. of water. Here 
the lettuce and peas were permanently injured, while tlie tomato seeds 
suft'ered only sufficiently to cause a delay in the rapidity w^ith which 
they germinated. The cab1)age seed was retarded with 2 cc and a 
lowering of the final percentage of germination with 3 cc. of water. 
The onion seed, being very sensitive to these unfavoi'al)le conditions, 
deteriorated very greatly, being practically worthless where 3 cc. of 
water were added. A l)rief study of the table will readily show that 
many seeds were killed at the still higher temperatures of 30 to 32' ' 
C. and 37- to iOo C. The onion seed was slightly injui-ed even where 



KFFEOT OF DEFINITE QUANTITIES OF MOISTURE. 4o 

no water was addod. However, a temperature of 40^ C. is suilicient 
to injure many seeds, even thoug-h the liberated water be permitted to 
escape, as is shown in the tests of the onion, No. 1539 of the table. 
The greatest injur}" when air-dried seeds are sealed in bottles and then 
sul)je<'ted to a Jiigher temperature is due to the increased humidity of 
the confined air, as a result of the water lil)erated from the seeds. 

At first glance some of the conditions given in the above talile may 
seem to be extreme and far beyond any normal conditions that would 
be encountered in the ordinary handling of seeds. This may seem to 
be especially true Avith tlie seeds kept in the bottles with 8 cc. of 
water where the additional amount of moisture absorbed gave ris(\ in 
some of the seeds, to a water content of approximately ^o per cent. 
Yet this need not be thought of as an exception, for such extrcMue 
cases are often encountered in the commercial handling of se(>ds. 
During the process of curing even more di-astic treatnuMit is not 
infrequently met with, Pieters and Bi'own" have shown that the 
common methods employed in the harvesting and curing of Pon jnut- 
ten!<iH L. were such that the interior of the ricks reached a tempei'a- 
ture of 180 to 110'^ F. (54.4^ to 60^' C.) in less than sixteen hours, at 
which temperature the vitality of the seed is greatly damaged and 
frequently entirely destroyed. The interior of one rick reached a 
temperature of 148 ' F. (64.4 C) in twenty hours, and the vitality 
had decreased from 91 per cent to 3 per cent, as shown by the ger- 
mination of samples taken sinudtaneously from the top and from the 
inside of the same rick. 

On the other hand, the extreme cases need not l)e considerinl. 
Take, for example, the onion seed that was sealed in a botth' with 
1 cc. of water and maintained at a temperature of 37 ' to 4(» C The 
increase in weight due to the water a])sor])ed was 3.91 per cent, thus 
giving a moisture content of 11.3 per cent and a complete destruction 
of vitalit}'. The cabbage seed, kept in the same bottle, had absoi'])ed 
a ([uantity of water equivalent to 3.35 per cent of its original weight, 
which, with the 5.90 per cent contained in the original sample, gave 
8.25 per cent of water. This sample of seed germinated only 11 per 
cent, having thus no economic value. In neither of these samples 
was the amount of water present in the seeds greater than that oi'di- 
narily found in commercial samples. Moreover, the temperature was 
much ])elow that frequently met with in places where scimIs are 
ofi'ered for sale and likewise well within the limits of the maxiuuun 
temperature of our summer months, especially in the Southei-n 
States. Take, by wa}" of comparison, the maxinunn tempcu-atures of 
some of the places at which seeds were stored to determine tiu^ efiect 
of climate on vitality, as shown in another pai't of this paper. During 



"Bulletin 19, liureau of Plant Industry, II. S. Department of Agriculture, 1902. 



44 



THE VITALITY AND GERMINATION OF SEEDS. 



the summer of 1!>()0 the muximum temperature at Waf^oner, Ind. T., 
was 107^ F. (41.1'^ C), while that of Lake City, Fla., was 103° F. 
(39.5° C). If these points are kept in mind, it is not at all surpris- 
ing- to find that seeds lose their vitality within a few weeks or months 
in warm, moist climates. 

In order to make the above facts more clear the preceding table has 
been summarized and is presented in the following condensed form, 
showing the relation of the water content of the seed to vitality: 

Tahle XI. — Mdrlcid (hiirioTdtimi in vitality 'ivith an increase in the (jiKoilIti/ <if the irater 

content of seeds. 



How preparations were made. 


Amount of water 

introduced into 

the bottles. 


Average in- 
crease in 
weight as a 
result of the 
greater water 
content. 


Average 
moisture in 
seeds at the 
time germi- 
nation tests 
were made. 


Average 
germina- 
tion. 


Control sample 


cr. 


Per cent. 


Per cent. 

(;.o7 

0. 55 
8.31 
9. 91 
ri. 75 
15. 10 


Per cent. 
93.3 


Closed bottles, sealed with paraffin 

Do . 


Water expelled. 
None. 
0.5 
1.0 
2.0 
3.0 


0. oc. 

.US 
1.75 
3.24 
r\ 91 
8.13 


(1 93. 9 
94. 


Do 

Do . 


91.7 

83. 3 


Do . . . 


(;7. 5 


Do 


58. 6 







'I Peas not included in this set. 

Numerous other results of a similar character might ])e cited, ])ut it 
hardly seems iiecessar}' at this time, since there can ]>e no doubt that 
moisture is the prime factoi' in causing the premature destruction of 
vitality in seeds in the usual conditions of storage. Why they lose 
their vitality :is a result of the unfavoral)le conditions is ((uite a difl'er- 
ent question, and has to do witli the very complex com})osition of the 
seed. 

A COMPARISON OF METHODS OF STORING AND SHIPPING SEEDS 
IN ORDER TO PROTECT THEM FROM MOISTURE AND CONSE- 
QUENTLY TO INSURE A BETTER PRESERVATION OF VITALITY. 

SUOGESTIONS OF EARLIER INVESTIOATOHS. 

As early as 1832, Aug. Pyr. De Candolle'* wrote a chapter on the 
conservation of seeds, in which he said that if seeds be protected from 
moisture, heat, and oxygen, which are necessaiy for germination, 
their vitality will be much prolonged; moreover, that if seeds are 
buried sufficiently deep in the soil, so that they are protected at all 
times from the very great influence of oxygen and moisture, their 
vitality will ))e preserved for a much longer period. 



«Physiologie Vegetale, Paris, 1832, Tome II, p. 618. 



COMPARISON OF MP:TH0DS OF STORING AND SHIITING. 45 

Gij^lioli" ooes so far as to i^iiy: 

There is no reason for denying the po.ssil)ility of tlie retention of vitality in seeds 
preserved dnring many centuries, such as the Mummy wheat and seeds from Pompeii 
and Herculaneum, jirovided that these seeds have been i)reserved from the begin- 
ning in conditions unfavoral.)le to cliemical change. * * * The original dryness 
of the seeds and their i)reservation from moisture or moist air must be the very 
first conditions for a latent secular vitality. 

Some of tlic earliest suoo-estions for storiiio" seeds in ([luiutity were 
made by Clement and Faz^-Pasteur, and were reported l)v Ang'. Pyr. 
De Candolle in liis Physiolog'ie Vej^'etale. Clement sno-o-^sted the use 
of laro-e east-iron I'eeeptaeles, made impervious to air and water, the 
well-dried seeds to he pouivcl in through an opeinno- at the top, after 
which the opening should be hermetically sealed and tiie seeds with- 
drawn through an iron pipe and stopcock at tlie bottom of the taidv. 
The scheme of Fazy-Pasteur was to store seeds in wooden boxes well 
covered with tar. This method was especially applicable to small 
([uantities of seeds, and was used to a limited extent at that time, but, 
so far as has been ascertained, it has long since been discarded. The 
keeping of seeds in large iron tanks, as suggested ])y Clement, lias 
never been practiced to any extent. It seems quite possible, however, 
that the present "'tank''' grain elevator, now so universally used, might 
readily he moditied in such a way as to make the method suggested by 
Clement (juite practicable. 

TlIK NKOKS.SITY FOR THOKOIKJHLY CURING AND DRYING SEEDS. 

In addition to being well matured and carefully harvested, seeds 
should be thoroughly cuj'ed and dried before ])eing put into the stor- 
age bins. Much better i-esults would ha o])tained if such seeds were 
artificially dried for several days in a current of dry air at a tempera- 
ture not to exceed 35 ' C. With this method of drying, from 2 to 4 
per cent of the moisture usually present in air-dried seeds is expelled. 
The accompanying contraction of the seed coats makes them more 
impervious to the action of moisture, and consecpiently the seeds are 
better prepared for storing and shipping. Experiments made with 
cabbage, lettuce, onion, and tomato seeds gave results as follows: The 
average loss in weight of the air-dried seeds, after an additional dry- 
ing of 30 days at a temperature of 30 ' to 32 ' C. was 2.7l> per cent. 
Yet these same seeds, when kept for 40 da^^s in the laboratory, reab- 
sorbed onl}' an average of O.'Jl per cent of moisture. Like ([uantities 
from the original sample gave only the slight variations ordinarily met 
with, due to the lumiidity of the atmosphere. Thus seeds, when once 
carefully and thoroughly dried, will not regain their original weight, 
provided they l)e kept in a dry room. 

« Nature, 1S95, 52: 544-545, 



4<) THE VITALITY AND GERMINATION OF SEEDS. 

CHARACTER OE TJIE SEED WAREHOUSE OR STORACE IIOOM. 

Another important factor in the storing of seeds is the character of 
the seed warehouse or storage room. The hrst point to l)e considered 
is dryness. Such houses should l)c kei)t as dry as possi})le, wliicli can 
be accomplished either by means of artificial heat or I)}' the use of 
strong dr3'ing agents, or better still, by both. True, if the seed ware- 
house be located in a section having a dry climate, this difficulty is at 
once largely overcome. But in many cases such a location is imprac- 
ticable or even impossible, and other means must ])e resorted to. As 
a matter of fact, most large seed warehouses are not heated and a 
great loss in vitality inevitably follows; but each seedsman nmst 
determine for himself whether or not this loss is sufficiently great to 
justify the expense of heating such a storage room. 

Experiments carried on during the progress of this work have 
shown some very marked differences in favor of seeds stored in rooms 
artilicially heated. The averages of the thirteen samples of seeds from 
the eight places at which they were stored show a diti'erence in the 
loss of vitality of i>.87 per cent. Those kept in rooms that were arti- 
ficially heated during a greater portion of the time deteriorated 25.01 
])er cent, while those stored in rooms not so heated deteriorated 35.78 
per cent. The loss here given for seeds stored in dry rooms is greater 
than such conditions warrant, owing to the very unfavorable condi- 
tions at Mobile, Ala., and Baton Kouge, La. At Lake Cit}', Fla., the 
relative percentages of deterioration were 29,-1:2 and 1(5.27 for the 
unheated and heated rooms, respectively, at Auburn, Ala., 33. IH) and 
10.34 per cent, and at Durham, N. H., 39.58 and 3.57 per cent, respec- 
tively. Unfortimately these experiments were not made with this 
definite point in view, and the results are not entirely satisfactory', as 
no records were made of the temperatures and humidities. 

THE VALUE OF (JOOD SEED TO THE MARKET GARDENER. 

This work was undertaken chiefly for the purpose of finding some 
improved methods of shipping and storing seeds in small packages, 
wherein their vitality might be better preserved. The rapid deterio- 
ration in vitality causes great losses to gardeners living in districts 
whei'c the climatic conditions bring about the premature destruction 
of vitality in seeds. In many cases the seeds are practically worthless 
or altogether fail to germinate after a few weeks' exposure. The loss 
in such cases is not in the greater quantity of seed required, but the 
retardation or complete failure of the germination often means dela}^ 
making the difl'erence between success and failure in the desired crop. 
Seed of low vitality is even worse than dead seed. With the latter the 
difKculty is soon discovered, while with the former, although the seed 
will germinate, the seedlings are not sufficiently vigorous to develop 



COMFAKISON OF MP:THUL)S OK STOKINU AND yiUPriNG. 47 

into stroiii;' and healthy phints. True, most eiiter])i'isinij;- oaicleners 
usually hu\ t> \ itality tests made immediately pi'ei)arat()iT to plautiut^', 
but this is not always convenient, and they rely on the residts of tests 
made at some earlier date. In such cases it quiti; fre([uently happens 
that tlu'V accept the results of tests made several weeks earlier. With 
n)any seeds this will suftice, yet there ai'c many others that will dete- 
riorate very materially within a few weeks or ev(m within a few dti^'s 
in such unfavorable climates as exist, for example, near the (Julf of 
Mexico. In a letter dated January 15, li>()o, Mr. J. Steckler, of New 
Orleans, La., wrote as follows concerning" the vitality of seeds: 

Some iset'dH lire not worth l>ciii.ir I'l'i'itrd afttT lieiii.!,' lieTi- Illicit iiioiitlis. 'I'lii.s in 
especially true of cauliflower j^eed. We havenuule reju-ated Icsls and this seed after 
reuiaining here IK) dayn was worthless and had t(j be thrown away. 

SI1II'1'IN(J SEKDS IN ("HAKCOAL, IMOSS, ETC. 

Bornt'maim" miide some ex})erinients with seeds of V'n-toi'in rafia 
and Juiri/ale fci'iKr, in which he found that when packed in powdered 
charcoal they soon lost their vitality, but when packed in powdered 
chalk sliolitly t)etter results were obttiined. On the other hand, 
Dannner* reconunends powdered charcoal as a method of packini^- for 
seeds that lose their vitality during- shipment, especiallv the seeds of 
palms and a numl)er of the conifers. 

Charcoal is undoubtedly much blotter than moist eartli or mt)ss. 
which arc fre(iuently used, the latter ati'ordino al)undant opporturiities 
for the develo])ment of molds and bacteria durino- transit. Some such 
method as moist charcoal is necessary in case of seeds which lose tlieir 
vitality on becomino- dr}'. Numerous other reports have ])een pul)lished 
from time to time concernino- the shippino- of seeds of aipiatic i)hints, 
tis well as those of low vitality, but they need not be discussed further 
at this time. 

NATURE OF THE KXrERIMENTS. 

Aside from some ])opular accounts and miscellaneous suggestions, 
but little has been done toward tindino- improved methods of shipping 
and storing- seeds of our common plants of the garden and field. 
Accordingly', in February, 1900, a scries of experiments was under- 
taken to determine some of these factors, in Avhich three (Questions 
were considered: (1) How may small quantities of seeds be put up so 
as to retain a maximum germinative energy for the greatest length of 
time? (2) What inmiediate external conditions are best suited for the 
longevity of seeds ^ (3) What part do climatic conditions play in 
alf ectiug the life of seeds 'i 

« Gartenflora, 35. Jahrg., 188G, pj). 5;^2-534. 
&Ztschr. trop. Laudw., Bd. I, 1897, No. 2. 



48 THE VITALITY AND GERMINATION <>E 8EED8. 

In order to answer the lir.st (lue.stion, du[)licatc samples of the various 
kinds of seeds were put up in double nuinila eoin envelopes, as 
descri))ed on paoe 14. Likewise, duplieate sann)les were put up in 
small bottles, the bottles l)eing closed w^ith good cork stoppers. Some 
of the bottles were tilled with seed, while others were only partly full. 
In some cases there was a surplus air space live times as oreat as the 
volume of the inclosed seeds. This space, however, had no bearing 
on the vitality of the seeds as far as could )>e determined. 

In order to determine what immediate external conditions play an 
important part in the destruction of vitality, samples of seed, ])repared 
as above described, were stored in dilierent places." At each place 
they w^ere subjected to three different conditions of storage, which, for 
convenience, have ])een designated as '"trade conditions," "dr}' room," 
and ''basement,*''' as described on page l-t. In addition to these three 
methods of storage, numerous other conditions were tried in and near 
the lab(^ratory ; such as in incubators at increased temperatures and with 
varying degrees of moisture, in cold storage, in greenhouses, and in 
various gases, in vacuo, in liquids, etc. 

The third question, '" What part do climatic conditions play in affect- 
ing the life of seeds?" has been answered for the most part in a dis- 
cussion on the effect of climate on vitalit}^ page 13. In fact, the seeds 
in the envelopes kept under trade conditions were the same in both 
cases, being used here simply as a means for (^omparing the vitality of 
seeds when stored in paper packages and in ])ottles, as well as to show 
the relative merits of trade conditions, dry rooms, and basements as 
storage places for seeds. 

DISPOSITION OF THE SAMPLES. '' 

A more definite description of the treatment given the seeds in the 
various places may be summed up as follows: 

K(/) Jt/(u/, P. R. — The seeds were sent to San Juan on February 9, 
IIXX), and were returned on June 20, 1900, after a lapse of 181 days.'' 
At San Juan the seeds were stored under trade conditions only, and 
the various packages were not removed from the original 1)Ox in which 
they were sent. While in San Juan the l)ox containing the seeds was 
kept in a room well exposed to climatic influences, being protected 
only from the direct rays of the sun and from rain. 

« San Juan, 1*. E. ; T^ake City, Fla. ; Mo))ile, Ala. ; Aul)urn, Ala. ; IJatun Rouge, La. ; 
Wagoner, Inil. T. ; Durham, N. IL, and Ann Arbor, Mich. 

^ The places of storage represented by trade conditions have already been dei-^crihed 
for each of the localities, but it seems advisable to rewrite the descriptions here so 
that they may be more readily compared with the dry room and Inisenient conditions. 

<-"The exact time that the seeds remained at San Juan was much less than 131 days, 
the time of transportation being included, as has been done for the other places. 



(^OMrAKlSoN OK METHODS OF STOKINO AND SHIPPING. 49 

Lake C'ltij^ Flit. — The seeds were sent to Liikr City on Fehnuiry 1», 
l!H)(>. The tirst complete set was returned on ,Iune IS, after 121» (hiys. 
The second complete set was returned October 1, after 284 days. The 
"" trade conditions '' at Lake City were supplied hy keeping;- the .seeds 
in a small, one-story frame building, the dooi'sof which were open the 
o-reater part of the time. This building was not heated, and the seeds 
were stored approximately 5 feet from the ground. *' Dry room" 
conditions were those of a storage room on the fourth lloor of the 
main building of the Florida Agi'icultural C'ollegc. Tiic third set was 
kept in a small bulletin room in the basement of the same building. 

2Iohlle, Al((. — The seeds were sent to Mot)ile on lu'bruary IT, l'.H)(». 
One set was received in return on fluly 7, after ISO dtiys. The other 
set was received on November (!, after 2()2 days. The ''ti'ade condi- 
tions'' in this case consisted of a comparatively open attic in a one-story 
frame dwelling. The set in a '"'dry roonr' was kept in a kitchen on a 
shelf 5 feet from the Hoor, and not more than t! f(H't distant from the 
stove. Here they were subjected lo the action of arti ticial heat through- 
out the entire period." The seeds under ''basement'' conditions were 
kept in a small cellar, which during the season of IIKK) was very moist. 

Aahuni, Ala. — The seeds were sent to Aul>urn on February 17, 
loot). The first complete set was received in return on May 30, the 
sei'ond on Noveml)er 1!) of the same year, or after 1(»2 and 275 days, 
respectively. ''Trade conditions '' consisted of an oilice room coimected 
with a gre(Mihouse, with the doors freciuently standing open; "dry 
room" conditions were obtained in the culture room of the biological 
lal)oratory on the third floor of the main building of the Alabama 
Polytechnic Institute, "basement'"' conditions being found in the base- 
ment of the same building, a comparatively cool situation, yet with a 
relatively high degree of humidit3^ 

Baton Romje^ La. — The seeds were sent to Baton Rouge on February 
17, 1900. On June IS the tirst complete set was received in return. 
The second set remained until October 22, making the time of absence 
121 days for the first and 247 for the second set. "Trade conditions" 
at Baton Rouge were furnished l)y keeping the seeds throughout the 
entire time of the experiment on shelves in a grocery store, the doors 
of which were not closed except at night. These conditions were thus 
identical with those to which seeds are subjected when placed on sale 
in small stores. The "dry room" was a class room on the second floor 
in one of the college bidldings. A storeroom in the l)asement of a 
private residence, having two sides Availed with brick, furnished 
"basement" conditioiis. 

«Presmnal)ly these were iu a dry i)lace, but further evidence showed that the pre- 
sumption was erroneous. The vajiors arisinji while eooking was being done on the 
stove gave rise to conditions very detrimental to a prolonged lifci of the seeds. 
25037— No. 58—04 4 



50 THE VITALITY AND GERMINATION <)F SEEDS. 

W(i(jo)U'i\ Lid. T. — The ycedt? were sent to Wagoiier uii February 
17, 1900. The lirst series was received in return on June 23, after 126 
days; the second set was returned after 238 days, on Octo])er 13, 1000. 
The sets for *■ ' trade conditions " were kept in a drug store, on a counter 
near an open door. The "dry room'' was a sleeping room on the first 
floor of the same building, while ''basement" conditions were supplied 
by keeping the seeds in a large depository vault in a bank. 

DuTliaiii., N. 11. — The two sets of seeds were sent to Durham on 
February 17, 1900, and were returned on July 14 and October 20, after 
117 and 231 days, respectively. The seeds under "trade conditions" 
were kept over a door at the entrance of one of the college buikliugs. 
The door opened into a hall, which led into office rooms, the chemical 
laboratory, and the basement. An oifice room on the first floor of the 
same building supplied "dry room" conditions. The seeds were 
located well toward the top of the room, which was heated with steam 
and remained quite dry at all times. The "basement" conditions 
were found in a storage room in one corner of the basement of the 
same building. 

Ann Arhoi'., 3fich. — The set of samples placed under "trade condi- 
tions" was kept in the botanical lal)oratory, l)eing moved about from 
time to time in order to supply the necessary variations to an herbarium 
room, to an open window, and to an attic. From February IS, 1900, 
until Ma}' 12, 1900, the set of seeds under "diyroom" conditions was 
stored in a furnace room. The seeds were only a few feet from the 
furnace and were always quite dry and warm: The maximum tem- 
perature recorded was iS'-" C, with a mean of 38-' during cold weather, 
and of 30'^' C. during milder weather. On May 12 this set of seeds 
was transferred to the herbarium room on the fourth floor of the 
botanical lal)oratory, where they remained until vitality tests were 
made. " Basement" conditions were found in a fruit cellar, having 
two outside walls and a temperature fluctuating between 10*-^ and 13'- C. 

These packages and bottles were all securely packed in new cedar 
boxes from which they were not removed until after their return to the 
laboratory. 

RESULTS OF THE (4EKMINATION TESTS. 

After receipt of the seeds, germination tests were made as rapidly 
as possible, the results of which are given in the tabulations which 
follow. Likewise, in each case is shown the vitality of the control 
sample. Furthermore, a summary' of each table is given, showing the 
average percentages of germination of the seed from the various 
places for the first and second tests, respectivel}^ From these results 
the average percentage of loss in ^'itality has been calculated, reckoning 
the germination of the control sample as a standard. It is thus a verj^ 
simple matter to compare the relative merits of the diflerent methods 
of storing and the rob' th(\v play in promoting the longevity of seeds. 



COMPARISON OF METHODS OF STORING AND SHirPINCJ. 51 

Table XII. — I'crcciildijc of (jcrintiKtiioii. nf honis snlijcded h> rorioas (-(jiKlitiunfi of nlordije 

in d[lferciil lucdlilies. 

[(Jerniiniition of control sample: First test, 98.7 per cent; second test, 98.7 per cent.] 





ige. 


Order of 
tests. 


Nnm- 

l)cr of 

days in 

storage. 




Percentage of 


germination. 




riace of stor. 


Trade con- 
ditions. 


Dry rooms. 


Basements. 




Envel- 
opes. 


Bottles. 


Envel- 
opes. 


Bottles. 


Envel- 
opes. 


Bottles. 


Lake City, Fla 

Do 


First.... 


129 
•J3I 

102 

110 

121 
217 

IIJI 


98 
81 

98 
50 

58 


90 
00 

100 
90 

90) 

82 

100 

78 

98 
100 


98 
98 

97. 5 
98 

90 
90 

100 
96 

100 
98 

90 
100 

100 
90 

81 
100 


98 
90 

100 
91 

82 


92 
28 


98 

98 

100 

98 

100 

98 

100 
100 


80 


97. 9 



54 



98 
100 


Aulmrn, Ala 


First.... 
Second . 

First 

Second . 

First.... 
Second . 

First. . . . 


97 5 


Do 


100 


Mobile, Ala 

Do 


100 
98 




98 


Do 


98 






Do 












First. . . . 


120 

238 

147 
251 


98 

100 
98 

98 
100 


100 
100 

98 

90 

HI 

91.5 


100 

84 

100 
92 

98 
92 


98 


Do 


98 




First 

Second . 

First 


100 


Do 


98 




92 


Do 






100 




tage of ger- 

age of gain 
ity. 


[First.... 
[Second . 

(First.... 
jSecond . 






Average i)ercen 
mination. 


128 
251 


93 
09.50 


90. 4 1 
97 


95. 13 
09. 33 


97. 1 1 
97. 30 


00. 99 
55. GO 


97. 04 

98. 86 


Average percen 
or loss in vita. 


128 
251 


5. 78 
29. 59 


2. 29 

1.72 


3.31 

29. 70 


1.58 
1.30 


32.13 
43.01 


l.OG 
+ 0.10 



The beans at Mol)ile were seriously affected under all conditions 
except when put up in bottles and thus protected from the moist 
atmosphere. Those kept in bottles under "trade conditions" deteri- 
orated to 90 per cent, l)ut the result of the tirst test of tht^ same series 
indicates that some moisture passed through the cork and thsit the 
seeds were injured in that way. 

At Baton Rouge the beans retained their vitality somewhat better; 
but even here all those from the envelopes were practically worthless 
after 2-t7 days, for l)eans that germinate only 60 per cent arc of no 
value for planting. 

The "trade conditions" at Auburn, Ala., and Durham, N. H., were 
also very unfavora])le to the prolonged vitality of the beans. At 
Wagoner, Ind. T., San Juan, P. 11,, and Lake City, Fla., there was a 
marked deterioration, yet not suflicientl}^ great during the time g^ven 
to render them worthless for planting. However, it is quite evident 
that beans subjected to such conditions of storage would not be tit for 
planting the second season. 

A summary of the table shows that the vitality of the l)eans when 
kept in bottles and subjected to either of the three conditions was not 
interfered with. The averages show a variation of less than 2 per 
cent. With those kept in paper packages the results were quite dif- 
ferent, the advantage being slightly in favor of the "trade condi- 
tions." The loss in vitality was 2\>.r)9, 29.70, and IS.fil per cent, 
respectively, for "trade conditions," "dry rooms," and "basements." 



52 



THE VJTALITY AND GERMINATION OF SEEDS. 



Table XIII. — I'crceidaiji' of grnnnudion of pcdK subject <( I to variuus conditions <f Kturuxje 

in different localities. 

[GermiiiM tioii of control snmple; First test, 95.3 per cent; second test, 'jri. 7 per cent.] 



riiicc of storage. 



Lake City, Fla 
Do 

Auburn, Ala .. 
Do 

Mobile, Ala . . . 
Do 



Baton Rouge, La . 
Do 

San .hum, I'. R . . 
. Do 



Wagoner, Did. T 
Do 



Durliaiii, N. II. 
Do 



Ann Arlior, Mich. 
Do 



Average jicrccntage of ger- 
mination. 

Average percentage of g;iin 
or loss in vitality. 



Order of 
tests. 



Num- 
ber of 
days in 
storage. 



First.... 
Second . 

First.... 
Second . 

First 

Second . 

First.... 
Second . 

First.... 
Second . 

First.... 
Second . 

First.... 
Second . 

First.... 
Second . 



[Finst.... 
ISecond . 

I First.... 
Isecond . 



129 
231 



275 
140 



121 

217 



126 
238 

147 
251 



12.S 
251 



128 
251 



Percentage of germination. 



Trade condi 

tions. 



Envel- 



9C) 
SO 

93. 3 
97. 9 

(19. 2 
44 

94 
80 

94 
98 

98 
80 

98 
94 

90 

98 



Bottles. 



91.56 
84. 74 



3.92 
11. 45 



97. 

9S 

94 
91 

92 
100 



100 

98 

90 
92 

94 

98 

94 
94 



94.24 
95. 25 



1.12 
0.47 



Envel- 



94 

92 

87. 8 
90 



100 
94.' 

94 
94 



93.4 
80. 45 



1.99 
16. 94 



Bottles. 



94 

92 

97. 8 
96 



91.41 
95. 14 



4.08 
0.58 



Basements. 



Envel- 
opes. 



81. 44 
60. 66 



14. 55 
36.62 



Bottles. 



94 

100 



95. 43 
96. 28 



+0.14 
+ 0.60 



The peas retained tlieii- vitality much })etter than the beans. How- 
ever, the greatest loss in both peas and beans was in the envelopes at 
Mobile and Baton Rouge. Some of the samples from the envelopes 
germinated fully as well or even better than the control, ])ut the gen- 
eral averages of the second tests for all of the localities show a loss of 
11.45 per cent in ''trade conditions," 15.91 per cent in "dry rooms," 
and 8<).03 per cent in "Ijasements." The beans under identical condi- 
tions lost 2!).5!>, 20.76, and i;].«)l per cent, respectively. 

The seeds kept in bottles deviated but very little from the .standard 
of the control. 



COMPA.RISON OF METHODS OF STOKINO AND SHirPINd. 



53 



Table XIV. — Prrrnilagr of (fi'rini)i<ill(in of cohhogr siiliji'clcd to rorloiis condllio)is of 

.storage ill dlJfiTciit lorolitit's. 

[Germination of control sample: First test, 92.7 per cent; second test, 92.4 per cent.] 





Order of 

tests. 


Nnm- 

l)er of 

days in 

storage. 


Percentage of germination. 


Place of storaRO. 


Trade condi- 
tions. 


Dry rooms. 


Basements. 




Envel- 
opes. 


Bottles. 


Envel- 
opes. 


Bottles. 


Envel- 
opes. 


Bottles. 


Lake City, Fla 


First.... 


129 
281 

102 

27r) 

140 

2(12 

121 

247 

131 

V2f, 

2as 

147 

251 


89. 5 
(«. 5 

91 
01.5 

04. 5 
17 

.88. 5 
25. 5 

82 
70.2 

83. 5 
70. 5 

93 
12 

90 
91 


92. 5 
89. 5 
90.5 
90 

93. 5 

87. 5 

93 
90.5 

95. 5 
89 

93 
91.5 

97. 5 
92. 5 

92 
94 


89. 5 
81.5 

89. 5 
90 

.58. 5 

90. 5 
11.5 


94 

89. 5 

81 

89 

90 
95 

91 

80 


80. 5 
14. 5 

92 
00 

.58. 5 

79. 5 
0. 5 


90. 5 


Do 


94.5 


Anbnrn, Ala 


First.... 


91 


Do 


85. 5 




First 

Second . 

First.... 
Second . 

First.... 
Second . 

First 

Secr)nd . 


92. 5 


Do 


91 




94 


Do 

San Juan P R 


90. 5 


Do 












91 

89 
9:! 

94 

88 


95. 5 
92. 5 

90 
95. 5 

90. 5 
82 


88. 5 
70. 5 
95. 5 
92. 5 

89. 5 
70 


97.5 


Do 


S9 


Durham, N. H 


First.... 
Second . 


94.5 


Do 


90. 5 




94. 5 


Do 


Second . 

fFir.st 

jseeond . 

(First.... 
(Second . 




95. 5 








Average percentage of ger- 
mination. 


128 
251 


SO 
52. 15 


93.47 
90. 50 


80. 43 
01.5 


92 
89. 93 


84. 29 
53.33 


93. 5 
92. 21 


Average percentage of gain 
or loss in vitality. 


12.S 
251 


7.23 
43.56 


+ 0.83 
1.94 


r>. 77 
33. 44 


0. 80 
2. 07 


9.07 
42. 29 


+ 0.80 
0.22 



Table XIV shows that the cahhage, like the peas, was injured to a 
less deofree at Mobile and Baton Rouge than the beans, ])ut even the 
("abl)age seed kept in the paper packages in these cities were all ))ut 
killed. The average degree of injury, however, was greater in the 
cabl)age than in the l)eanH. In a majority of cases there was more or 
less deterioration in the case of this seed kept in the envelopes. Aside 
from those already mentioned, the trade conditions at Durham, N. H., 
and the basement at Lake City, F\a., should be expressly noted. 

The seeds kept in the l)ottles deviated l)ut little fi'om the control, 
while those kept in paper pacivages germinated only .5!^. 15, HI. 50, 
and 53.33 per cent for thi^ trade conditions, dry room, and basement — 
equivalent to a loss in vitality of 43.5(), 33.44, and 4i}.iill per cent, 
respectively. 



54 



THK VITALITY AND GEKMINATION OF SEEDS. 



Table XV. — I'lmiUagr of (jn'in'i nation of radisJt suhjcctcd to vorioux condilionx of storage 

in diffnrtit localities. 

[Gcrmin;iti<in of control sample: First test, S3.G per cent; second test, 7S.S per cent.] 





Order of 
tests. 


Nnrn- 

l)er of 

days in 

storage. 




Percentage of germin 


ition. 




Place of stora^'C. 


Trade condi- 
tions. 


Dry rooms. 


Basement.s. 




Envel- 
opes. 


Bottles. 


Envel- 
oi)es. 


Bottles. 


Envel- 
opes. 


Bottles. 


Lake (Mtv, Fhi 


First 


129 
234 

102 
275 

140 
262 

121 
247 

131 


79 
58. 5 

k' ' 

58. 5 
51 

77. 5 
55. 5 

(U 
62 

77.5 
60. 5 

80.6 
59.5 

82.5 

77.5 


78. 5 
64 

85 

81 
71.5 

85. 5 
69. 5 

.81.5 
73. 5 

80. 5 
75. 5 

75. 5 
81.5 

85 
HO. 5 


84.5 
67.5 

,S5. 5 
66 

5(i. 5 
49 

73. 5 
49. 5 


75 
71.5 

80.5 
73. 5 

81 
70 

78. 5 
74.5 


66 

48. 5 

86. 5 
60. 5 

75 

61.5 
51 . 5 


83 


Do 


67 


Anhurn, .Ma 

J)(i 


First.... 
Second . 

First. . . . 


.85. 5 
76. 5 


Mobile Ala, 


76 


Do 


7'> 


Baton RoHKc, La 

Do 


First 

Second . 

First.... 


78.5 
75 






Do 










Wagoner, Did. T 


First.... 
Second . 

First 


120 
23.S 

147 

2.'il 


79 

76. 5 
74.5 

82. 5 
79. 5 


84 
77 

85 

85 
70. 5 


.SO. 5 
63 
81 
68 

78 
62. 5 


86. 5 


Do 


70. 5 
74 


Do 


79 




First 


82. 9 


Do 


SiK'ond . 

[First.... 
[Second . 

(First.... 
jsecond . 




78. 5 






AveraRe i)ercentage of gcr- 
ininalion. 


128 
2.51 


74.39 
60. 94 


81. .56 
73. 56 


76. 8(; 
64. 33 

8. 07 
18. 37 


80. 5 
72. 71 


75. 5 
59 


80.91 
74.07 


Average percentage of loss 
in vitality. 


128 
251 


11. 02 
22. 67 


2. 44 

6. 65 


3.71 


9. 67 
2.5. 13 


3. 22 
6 



The results of the tests of the radish seed are very similar to those 
of the ('a))l)at>-e; the latter, however, showed a greater loss in vitality. 
As shown by the second tests, the averaj^c percentau-es of deterioration 
of the eal)l)age seed which was kept in the envelopes were as follows: 
Trade conditions, 43. 5() per cent; dr^^ room, 33.44 p(M- cent; ])asement, 
42.'29 per cent, while the loss in vitality of the radish was only 22.67, 
18.37, and 2.5.13 per cent, respectively. 



(U)MFARIS(»N OK MKTHODS OF STORTNO AND SHIIM'TNO, 55 



Table X\'1. — J'l rcnihit/c of (/truiiiKilinu offdrnil sidijci-li'd in nirloim cniKJilioiiK of storage 

in. (lijl'i'i-i'iil locdlit'ii's. 

[Germination of control siini]ile: First test, .SH.H i>er cent; second test, S2 per cent.] 





Order of 

tests. 


Nnm- 
lier of 
days in 
stoVage. 




Percentage of 


germination. 




riace of stomK(>. 


Trade condi- 
tions. 


Dry rooms. 


Basements. 




Envel- 
opes. 


Bottles. 


Envel- 
opes. 


Bottles. 


Envel- 
opes. 


Bottles. 


Lake ( 'itv, Fla 


First.... 
Second . 

First.... 
Second . 

First.... 
Second . 

First 

Second . 

First 

Second . 

First 

Second . 

First.... 
Second . 


129 

102 

HO 
202 

121 
217 

i:u 
120 

2;!s 

147 

2r.i 


70. 5 
4:i. 5 

.H4.5 

;{o 
5y 

S. 5 

"1.:! 

71.5 
4S. 5 

SI. 5 
4-.) 

7.S 

70 
SO 


s:i 

so. 5 

82 
70.5 

S7. 5 

so 
S2. :? 

S2. 5 

si;. 5 

S2 

51. 5 

52. 5 
S5. 5 

7'.l 

7s 


78 
0)7. 5 

83 

51.5 

75. 1 
10.5 


7S. 5 
78. 5 

SC) 
70. 5 

83. 5 
0',) 

80. 8 


73 
3 

80. 5 
47. 5 
20.5 

57. 3 



, J. 


Do 


SI 5 






11(1 




Mohile, Ala 

]>o 


s7 


Baton Kon.i,'-e, La 

1), , 


82. 3 
39 


S:ui .Iiian, I'. 11 




Do 




L 




VVai,'oner, Did. T 


SI 
S7.5 

s:; 

78. 5 


81 
SI 

85. 5 
.85. 5 

8U 


45! 5 

S3. 5 

78 
58. 5 


s" 5 


J)o 


84 


Dnrham, N. H 

Do 


.S2. 5 
87 5 


Ann .\rbor Mich 


S3 5 


Do 


Second . 

(First.... 
[Seconil . 

(First.... 
|Second . 




71 


Average percentage (>f ger- 
mination. 


128 
251 


75. 10 
37.31 


S2. 
SO. S7 


70. 01 
53. 83 


82. 4 
74.71 


08. 04 
37.75 


83. S3 
75.21 


Average percentage of gain 
or lo.ss in vitality. 


12H 
251 


y. 72 
54.5 


0.84 
1.38 


S. 75 
34. 35 


1 . 08 
8. 8'.» 


18.32 
53. 90 


f 0. 03 
9. 5 



T!il)le XVI shows results vory siinilar to those of Tal)le XV, except 
that the carrot was aft'ected sliohtly more tlian the cabbaye. There 
was also a g-reater falliiiootl' in the case of the seeds kept in tlie bottles 
in dry rooms and basements. The reason for this is not very clear. 
Apparently it was due to some local conditions, inasmuch as it was 
confined chiefly to the bottles kept at Mo])ile and liaton Kouu-e. The 
average results of the germination tests of the se(>ds kept in packages 
are quite low for the carrots. Seed from trade conditions germinated 
87.81 i)er cent, from basements 37.(57 per cent, and from dry rooms 
53.88 per cent, with a loss in vitality of 54.5, 54.()«», and 84:.8(» per 
cent, respectividy. Undin* similar conditions the cabbagt* lost in vital- 
ity 48. 5G, 42.j}8, and 88.45 per cent, r(\sp(^ctively. 



5() 



THE VITALITY AND (JERMINATION OF SEEDS. 



Table XVII. — PercpnUKjr of gtrminnfmi of " yl " sveet corn xuhjected to rnrious condi- 
tions of storage in different localities. 

[Germination of control sample: First test, 92.7 per cent; second test, 92.4 per cent.] 





Order of 

tests. 


Num- 
ber of 
days in 
storage. 


Percentage of 


germination. 




Place of storage. 


Trade condi- 
tions. 


Dry rooms. 


Basements. 




Envel- 
opes. 


Bottles. 


Envel- 
opes. 


Bottles. 


Envel- 
opes. 


Bottles. 


Lake Cilv, Fla 

Do " 


First 

Second . 

First.... 
Second . 

First 

Second . 

First 

Second . 

First.... 


129 
234 

102 

27.5 

140 
2(')2 

121 

247 

131 


94 
92 

90 

88 

80 
20 

9('i 

88 

9r. 

92 

90 
90 

100 
9fi 

100 

98 


9G 
100 

98 
98 

100 
96 

94 

96 

94 
94 

98 
96 

92 
96 

86 
98 


94 

96 

94 
94 

80 
26 

96 

88 


92 
90 
9S 
90 

96 
100 

88 
96 


88 
54.5 

100 

80 

94.1 

86 
14 


98 
100 


Au))urn, .Ma 

Do 


92 
100 


Mobile, .Via 

Do 


96 
96 


Baton I{(Wge, La 

Do 


100 
100 






Do 










Wagoner Ind. T 


First.... 


126 

238 

147 
251 


94 

95. 9 
96 

94 
100 


96 
96 

90 
96 

89 
96 


96 
92 

100 
100 

100 
92 


96 


Do 


94 




First.... 
Second . 

First 


96 


Do 


98 




96 


Do 


Second . 




98 




1 First.... 
[Second . 

[First.... 
(Second . 






Average percentage of ger- 
mination. 


12,S 
251 


94.75 
83 


94. 75 
96. 75 


92. 56 
83. 33 


94. 14 

94. 86 


94.87 
72.08 


96. 29 

98 


Average percentage of gain 
or loss in vitality. 


128 
251 


-1-2.21 
10.11 


-1-2.21 
-f4.71 


0.15 
9.81 


+0.01 
4-2.66 


-1-2.34 
22 


+3.87 
+ 6.06 



Tablk XVIII. — Percentage of germination of '^ B" sireet corn sidgected to rarions condi- 
tioni< of storage in different localities. 

[Germination of control sample: First test, 89.3 per cent; second test, 88.5 per cent.] 





Order of 
tests. 


Num- 
ber of 
days in 
storage. 


Percentage of germination. 




Place of storage. 


Trade condi- 
tions. 


Dry rooms. 


Basements. 




Envel- 
opes. 


Bottles. 


Envel- 
opes. 


Bottles. 


Envel- 
opes. 


Bottles. 


Lake Gity, Fla 


First.... 
Second . 

First.... 


129 

234 

102 

275 

140 
262 

121 

247 

131 


86 
77.1 

,ss 

62 

4S 
12 

80 
.54. 2 

72 
78 

70 

78 

89. 3 
82 

92 
80 


60 
2 

92 
56 

81.2 
.52 

82 
36 

72 
71.7 

82 
76 

69. 5 
91 . 8 

88 
92 


90 

64 

8(; 
82 

60 
16 

84 
66 




.s(; 

38 

S7. 5 
51 

91 • 
46 


76 
30 

86 
S2 

75 

61 

4. 5 


46 


Do 





Anbiirn, .Via 

])o 


84 
89. 6 


Mobile .Via 


Fir.st.... 
Second . 


86 


Do 


76 


Baton Konge, La 

Do 


First 

Second . 

First 

Second . 


88 
61.2 






Do 










Wagoner, Ind. T 


First 

Second . 

First.... 


126 

238 

147 
2.51 


90 
,S4. 2 

.SI 

,S8 
86 


88 
8S 

.83. 6 

.88 

48 
22 


81 

88 

80 
76 

88 
82 


81 


Do 


7(; 


Durham, N. H 


80 


Do 


.8.S 




First 


96 


Do 


Second . 




88 




JFirst.... 
[Second . 

(First.... 
[Second . 






Average percentage of ger- 
mination. 


128 
251 


78. 16 
65. 41 


78.31 
59. 70 


,83.17 
66.33 


75.01 

48 


79 
60.41 


80. 55 
68.40 


Average percentage of loss 
in vitality. 


12.S 
251 


12. 47 

26. 09 


12. 31 
32. .55 


6.87 
•J5. 06 


16 
45. 76 


11.54 
31 . 74 


9. 80 
22. 71 



COMPAIII^^ON OF METHODS OF SToKINd AND SHIl'PINO. i)i 

Tables XVII and XVII I ha\'o ])Con considerod togothor, siiu'(^ both 
have to do with the .saiiie variet}' of sweet corn. The dili'erence in the 
(juality of these two samples was quite marked when the seed was 
received. Germination tests were made January 30, 1000, arid showed 
J»4 per cent for the "A" and 8S per cent for the "B" c()rn. In 
Noveml)er, 1900, samples of seed from the same orig-inal packages 
were tested, giving a germination of 02.1 per cent and SS.,5 per cent 
for the "A" and "IV samples, respectively, as shown in the controls 
of the above tal)les. Thus, when two grades of corn are subjected to 
favoral)le conditions of storage, both are well preserved; but when 
subjected to unfavoralde conditions, the one of poorer quality is much 
more suscepti))le to injury. The "A'"' sample which was stored in 
envelopes in trade conditions lost 10.11 per cent, as compared with 
2(>.0 per cent for the "B" sample. The "A" sample Avhich was 
stored in dry rooms lost only O.Sl per cent, while the "'B''"' sample 
lost 25.0*] per cent. In basements, the "A'' saiuple lost 2o pei- cent 
and the " IV sample 31.74 per cent. In both samples the corn in the 
packages stored in the l)asement at Mobile was so l)adly molded at the 
time the second tests were made that they have been omitted from th(^ 
table. 

The most interesting feature in comparing the results of these two 
saiuples is found in the seed which was stored in the bottles. The 
average results of the "A'' sampl(>s show a nuich higher percentage 
of germination for those from the bottles than the control, while the 
averages for the " B '' sample were nuich lower than the corrc^spoiul- 
iiig controls. The average germination of the " 15 '"' sample fi'oni the 
bottles was 50.7 per cent foi" the trade conditions, IS per cent for dry 
rooms, and (>8.1 per cent foi' l)asements, or a loss in vitality of 32.. 5;"), 
15.7*), and 22.71 per cent, r(\spectively. This ditl'erence was due to 
two causes, first, a ditlerenct^ in the quality of tln^ seed at the ])egin- 
iiing of the experiment, and, secondly, the larger amount of w atcr in 
the second sampl(\ "I).'' The greater ((uantity of water present in 
th.(> seed gave rise to a more humid atmosphere after the seeds were 
put into the bottles, especially when su!)jected to higher temperatures 
than those in which the seeds had been previously stored. This is an 
important factor always to be borne in mind when si^eds are put up in 
closed receptacles; they nuistl)e well (hied if \italitv is to be pinvserved. 



58 



THE VITALITY AND (iKRMINATlON OF SEEDS. 



Table XIX. — IWenitagr of (jmninaiion nf liitiire fudiji'dnJ In riirl(.iis cotKlitioiis of 
storage in differmt localities. 

[Germination of control sample: First test, 81.6 per cent; second te.st, 92.3 percent.] 



Place of storage. 



LiikeOitv, Fla. 
Do ..■ 

Auburn, Ala ... 
Do 

Mol)ile, Ala.... 
Do 



Baton RouKe, La. 
Do 



Sun .Tnan, V. R.. 
Do 



Wagoner, Ind. T . 
Do 



Durham, N. H . 
Do 



Ann Arlxir, Mich 
Do 



Average percentage of ge 
mination. 

Average percentage of lo: 
in vitality. 



Order of 

tests. 



First. . . . 
Second . 

First.... 
Second . 

First.... 
Second . 

First.... 
Second . 

First.... 
Second . 

First.... 
Second . 

First.... 
Second . 

First 

Second . 



First... 
Second 



P^irst. . . 
Isccond 



Num- 
ber of 
days in 
storage. 



129 
234 

102 
275 

140 
262 

121 
247 



126 

238 

147 

2r.i 



128 

251 



128 
251 



Percentage of germination. 



Trade 
conditions. 



Envel- 
opes. 



80. 06 
77.75 



1.89 
15.76 



84 
92 

85. 5 
90. 5 

78 

8S. 5 

81.5 
93. 5 



76 
92. 5 

80. 25 
93 

68. 5 
90 



80.15 
91. 12 



1.77 
1.29 



Dry rooms. 



Envel- 
opes. 



81 
92. 5 

88. 5 
90. 5 



s;!. 2i 
92 

84.5 
89. 5 



79.18 
78. 33 



2. 97 
1.5.14 



Bottles. 



81.14 
90.93 



. 56 
1.49 



Basements. 



68 
43. 5 

84. 5 
. 83. 5 



66. 28 
65.68 



IS. 78 
28. 95 



Bottles. 



77 
95.5 

88. 5 
90 

83 
91.5 

76 
92. 5 



75.2 
90. 5 

72 
91.5 



78. 31 
90.78 

~4. 03 
1.65 



The lottuco, has shown no very marked deviation from the controls, 
save tlie seeds from the packages kept at Mobile, and those which were 
stored in l)asements in envelopes at Baton Roiig(> and Lake City. 
The avin-age results of the second series of tests show a similar los.s in 
vitalit y of all of the seeds f r-oni the envelopes. The samples of seed from 
the bottles germinated practically as well as the controls. The results 
of the first series of tests arc not entirely satisfactory, none of the 
tests liaving gone to standard. The low germination of the lettuce in 
this series was due to inability to properly control the temperature in 
the germinating pans. The proper temperature for the successful 
germination of lettuce seed is 20" C. , while in this lirst series the ger- 
mination tests were unavoidably made at 26'^ to 27.5'' C. Neverthe- 
less, this seeming o])jection is of little consetjuence, since all of the 
results are directly comparable with the control. 



COMPARISON OF MP:TH0DS OF STORTNO AND 8H1PPIN(4. 



59 



Table XX. — Pirct/il(i(ji' of (jtriniiKilioii af (iii'ion siiltji'clc(J la rarlous (■(iiidilloiis of KlortKjt' 

■in. different localities. 
[(ioniiination of control sanij)le: First test, 96.8 per cent; second test, 97 per cent.] 





Order of 

tests. 


Num- 
ber of 
days in 
storage. 




Perec 


ntage of germin 


ition. 




Place of storage. 


Trade condi- 
tions. 


Dry rooms. 


Ba.sements. 




Envel- 
opes. 


Bottles. 


Envel- 
opes. 


Bottles. 


Envel- 
opes. 


Bottles. 


Lake City, Fla 


First.... 


129 
234 

102 
275 

110 

121 
247 

i:?] 

""■■i2.7 

2:{.s 

117 
2,'^l 


95 
IC). 5 

9(i 
12 



90 
0. 5 

84. 5 
50 

9:5. 5 
21.5 

9(;. 5 


95 

97.5 


95 
95. 5 

9(). 5 
90 
94.5 
91.5 

93 
97. 5 

98 
90. 5 

97. 5 
95 

91 ; 

97. 5 

90 
97. 5 


95. 5 
79 

90 
9(; 

11.5 


91 



95 
90 

9S. 5 
9S 

90. 5 
90.5 

93. 5 
()5 


SO 


97 

75. 5 
"O' 

35 



97 5 


Ho 


97 


Au))nrn, Ala, 

I)(i 


First.... 
Se(tond . 

First.... 
Second . 

First.... 
Second . 

First.... 
Second . 

First.... 
Second . 

First.... 
Second . 

F"i rst 


97. 5 
99 


Miil)ile, Ala 


99 


Do 


"(7 5 


Baton Konge, La. 

Do.... 


90. 5 
48. 5 


San ,Tnan, I'. K 




Do 










Wasfoner, Jml. T 


95. 5 

94. 5 
90 

99. 5 
95 


97 
97. 5 

90 
97 

97 
90. 5 


90) 
31 

93 
91 

93 

47 


94 5 


Di) 


97 5 


Durham, N. 11 

Do 


91.5 
9S 


Ann Artior, M ich 




Do 


Second . 

[First.... 
ISecond . 

1 First.... 
jsecond . 





98 


Averai^e iiercenta,!,'e of t;er- 
ininatiiin. 


12S 
2.M 


82.19 
25. 12 


95. SI 
90. 25 


S3. 79 
01 


90. 21 
92. 36 


81. 30 
33. 08 


90. 04 
90. 80 


Average iierccnta.ueof train 
or loss in vitalily. 


128 
251 


14. 20 
74.11 


+0.01 
1.20 


12. .53 
37. 12 


+ 0. 13 
4. 80 


1.5.07 
05. 90 


-K0.87 
0.33 



"'Phis lesl has not Ijcen inclm" 
niDldcd wlien put in test. 



'd in making up th(> averages inasmuch as the sei'ds were badly 



The onion seeds which were stored in the envelopes were veiy seri- 
ously affected in man,y of the places. Those from the basement at Lake 
City, from all of the conditions at Mobile, and from the dry room and 
basement at Raton Rouge were entirely killed. The seed from trade 
conditions at Raton Rouge germinated onl}^ 0.5 per cent. In many 
other cases the samples from the envelopes had become practicall}^ 
worthless. In only two instances was there any loss in vitality where 
the seeds were stored in bottles, viz, the second tests from the dry 
rooms and basement at Raton Rouge. These two tests have lowered 
the average results quite materially. If they were not included the 
averages would be raised to 90.91 and 97.90 per cent, respectively, 
instead of 92.36 and 90.86 per cent, as given in the table. The average 
percentages of germination of the seeds from the envelopes were very 
low in the second test, and were as follows: Trade conditions, 25.12 
per cent; dry rooms, 61 per cent, and basements, 33.8 per cent. This 
represents a loss in vitality^ of 7-1.11, 87.12, and 65.9 per cent, respec- 
tively. 

Onion seed is relatively short lived, and very easily affected l)y 
unfavorable external conditions. For this reason onion seed should 
be handled with the greatest care if vitality is to l)e preserved for a 
maximum period. This may be done successfully l)y keeping the dnj 
seed in well-corked bottles, or in ;iny good moisture-proof })ackage. 



60 



THE VITALITY AND GERMINATION OF SEEDS, 



Table XXI. — I'lrrrvtagr of (jrrminatinn of jvomi/ .vih/i-ctrd to vnriovs ronditions of 

storage in diff'rrrnt localities. 

[Germination of control sample: First test, G3 per cent; second test, 53 per cent.] 





f)t storage. 


Order of 
tests. 


Num- 
ber of 
days in 
storage. 




Percentage of 


germination. 




Place 


Trade 
conditions. 


Dry rooms. 


Basements. 




Envel- 
opes. 


Bottles. 


Envel- 
opes. 


Bottles. 


Envel- 
opes. 


Bottles. 


Lake (Jity, Fla 
Do 




First.... 


129 
234 

102 
275 

140 
202 

121 
247 

131 


44. 5 
1.5 

57.5 
2 

3 


28. 5 


20 
G.5 

48.5 
7.5 

o" 

53.5 
16.5 


63 
54 

08 
20.5 

57.5 
20. 5 

53 
34 

CO. 5 

58. 5 

61.5 
05 

00. 5 
60. 5 

51 
45 


45 
22. 5 

66. 5 

28 

2 


38 



.58. 5 
47 

62 
27.5 

61 
25. 5 

44 
17 


10.5 


60 


1 

4.5 



62.5 




57.6 




First.... 
Second . 

First.... 


69.5 


Do 


33.5 


Mobile Ma . ... 


.59 


Do 


2.5 


Baton Ronse, f ^a 

Do 


First 


54 
2.6 


San Juan, I'. R 
Do 


T 


First.... 
Second . 

First.... 
Second . 

First.... 












Wagoner, Iiid. 
Do 


126 
238 

147 
251 


50.5 

49.5 
44 

59. 5 
62 


62. 5 
.59. 5 
03.5 
00.5 

40 

48. 5 


40 
,S. 5 

49 
30. 5 

50 
3.5 


■59 




.52. 5 


Durham, N. H 

Do 


03. 5 
60 




First.... 
Second . 

[First.... 
isecond . 

JFirst.... 
[Second . 


53 


Do 




60. 5 




xTcentage of gcr- 
)n. 

[lerci'litage of lo.ss 
ity. 




Average 
minati( 


128 
251 


38.87 
8 


60. 12 
44. 75 


44.43 
24.41 


55. 93 
40. 80 


31.. 57 
8.08 


68. 64 
38. 43 


Average 
in vita 


128 
251 


38.3 
84.91 


4.57 
15.60 


29. 48 
.53. 97 


11.23 
23. 02 


49. 89 
84. 76 


6. 92 
27. 49 



Taulk XX II. — Percrvtage of germination of phlox drnmmondii snhjertrd to varioupt con- 
ditions of storage in different localities. 

[Ciermination of control sample: Fir.st test, 09 per cent; second test, .53.9 per cent.] 





Order of 
tests. 


Num- 
ber of 
days in 
storage. 


Percentage of germination. 


Place of storage. 


Trade condi- 
tions. 


Dry rooms. 


Basements. 




Envel- 
opes. 


Bottles. 


Envel- 
opes. 


Bottles. 


Envel- 
opes. 


Bottles. 


LakeCitv Fla 


First 


129 
234 

102 

275 

140 

■JIVi 

121 
247 

131 


41.5 

2. 5 

61.5 
1 

0.5 


47. 5 


23. 5 
11.6 

.50. 5 
,5.6 

67 
0.5 

67 
40 


78 

72. 5 
.5o! 5 

65 
51.5 

02. 6 

.5,S 

06 
01.5 

73. 5 

m 

74 
(12. 5 

66 
54 


02 


02 
13.6 

0.5 


43. 5 



02 
25. 5 

03 
59 

74.5 

6S.5 

.58. 6 
6S. 6 


20.5 


05. 6 

1 

0.6 




77.5 


Do 


03 


Auburn, Ala 


First 

Second . 

First 


07. 6 


Do 


06 


Mobile, Ala 


.5,8.6 




48 6 




First.... 
Second . 

First 

Second . 


70. 5 


Do 


01.6 






Do 












First.... 
Sec(md . 

First.... 


120 

238 

147 
251 


61 

62. 6 
33 

75. 5 
65 


70 

4.5. 6 
^.^0. 5 

09. 5 

.58. 6 


65 
9.6 

09. 6 
45. 6 

04. 6 
10. 5 


75 


Do 


47. 6 




71.6 




70 




First.... 


72 


Do 


Second . 




01 




[First.... 
[Second . 

[First.... 
[second . 






Average percentage of ger- 
mination. 


128 
251 


44.87 
7.62 


68.31 
68. 37 


52. 76 
17.91 


63. 28 
49.64 


41.07 
11.08 


70. 35 
59.6 


Average percentage of gain 
or lo.ss in vitality. 


12S 
251 


3t. 97 

85. SO 


1 

+ .S.27 


23. 54 

00. 78 


8. 29 
7.91 


40. 49 

79.46 


+ 2.01 
-1-10.39 



OOMPARISON OF MKTH(>DS OF 8TOKlN<} AND BHIPriNG. 



61 



Pansy iuul phlox have hocii considered to<;ether, siiiee their ])ehav- 
ior was ahiiost tlie same. Botli of the controls deteriorated to a con- 
siderable decree during- the V2r> days which elapsed between the time 
of the lirst and the second test, pansy losino- 15,87 per cent and phlox 
21.88 per cent. In both cases the mean loss in vitality of the seeds in 
the envelopes was very o-i-eat. The results of the second tests show a 
loss of 84.91 per cent for pansy, and 85.86 per cent for phlox where 
stored under trade conditions. In dry rooms there was a mean loss 
of 53.57 per cent for pansy and t!().78 per cent for phlox, and in base- 
ments a loss of 81. 7() per cent for the pansy and 79.15 per cent for the 
phlox. These results are obtained l)y considering" the second test of 
the control as a standard, the depreciation of the control l)eino- dis- 
reoarded. Some samples were dead and many more were of no eco- 
nomic value. It is especially interesting- to note how (luickly the seeds 
died at Mobile, Ala., there bein^- only a few g-erminable seeds at the 
end of 110 days. 

The behavior of the seeds in the bottles was more or less varitible. 
Some of the pansy seeds showed a hig'her vitality than the control, ])ut 
the averages were somewhat lower, the mean loss ranging frwn 15,60 
per cent under trade conditions to 27.1:9 per cent in basements, wdiile 
with the phlox the means for trade conditions and for basements were 
higher than the control ])y 8.27 and 10.39 per cent, respectively. 



Table XXIII. — Fercenhujcs <>/ (/cniiiudllon. of tomato Kuhjectcd to rorions conditions of 
doriuje in, (liji'crod loadittcs. 

[Geriniriiition of control siimple: First test, 95.5 i>er cent; second test, y7.5 per cent.] 





Order of 
tests. 


Num- 
ber of 
days in 
storage. 




I'ercentage ol 


germ in 


ition. 




I'lace of storage. 


Trade condi- 
tions. 


Dry rooms. 


Basements. 




Envel- 
opes. 


Bottles. 


Envel- 
opes. 


Bottles. 


Envel- 
opes. 


Bottles. 


Lake City, Flu 

Do 


First.... 
Second 


12'J 
234 

102 

275 

14t) 

2('i2 

121 
247 

131 

12(5 
117 

147 
251 


94 
94 

95 
>)4 

90 
79.5 

91.5 
9G 

94 

96.5 

96.5 
94 

94.5 

87 

89 
98.5 


94 

98 

94.5 

98. 5 

94.5 

97. 5 

95 

96. 5 
91.5 
94 5 

97 
98 

95 
9.S 

94 

98 


94 
91 

93. 5 
97 

91.5 

,S7 

91 
93 


95. 5 
97. 5 

97. 5 
91. 5 

96. 5 
95. 5 

95 
98 


88. 5 
77 

96 
98 

64.5 
19.5 

.S3. 5 
39. 5 


94 
97.5 


Auburn, Ala 


First 

Second . 

First 


94.5 


Do 


96.5 


Mobile, Ala 

Do 


93.5 

98 


Baton Rouge, La 


First 


95 


Do 


96 


San .Tuan I' K ' . 


First 




Do 










Wagoner, Ind. T 

Do 


First.... 
Seccind . 

Fir.'^t 

Second . 

First 


9S 

97 
97 

93 
98 


96. 5 

97. 5 

91 

99 

91.5 
97.5 


98. 5 
9.S. 5 

97. 5 
97.5 

89 
95 


96 
93. 5 


Durham, N. H 


96. 5 


Do 


97 




92. 5 


Do 


Second . 

[First.... 
[Second . 

jFirst.... 
[Second . 




98 






Average percentage of ger- 
mination. 


128 
251 


93.06 
92. 44 


94.81 
97. 31 


84 
94.33 


95. 21 
97.07 


88.21 
84. 25 


94.57 
97. 21 


Average percentage of loss 
in vitality. 


128 

251 


2. 56 
5.20 


0.72 
0.20 


1.57 
3.29 


0.30 
0.44 


7.64 
13.63 


0.98 
0.30 



62 



THE VITALITY AND GERMINATION OF SEEDS. 



The tomato need, a.s .shown in Tables V and XXV, was the most 
resistant to the nnfavorable conditions of storage. The seed in the 
bottles was not injured at any of the places. The lowest germination 
was 91.5 per cent from the seed kept in a dry room at Ann Arbor, 
Mich. The seed in the envelopes gave a much wider variation, falling 
quite low in some of the samples which were stored in the basements. 
The average losses in vitality for the entire series of the second set of 
seeds which were kept in envelopes were as follows: Trade conditions, 
5.20 per cent; dry rooms, 3.29 per cent; basements, 13.68 per cent. 
The average percentage of germination of the seed which was kept in 
th(; bottles differed from the control less than one-half of 1 per cent. 

T.u;lk XXIV. — Pcrmitiujc of (jermination of watermelon subjeclcd to various cunditions 
(f storage in different localities. 

[CiLTiniii.-iticiu i)f I'ontrol sample: First test, 95.5 per cent; second test, 99 per cent.] 



I'liiee of .storage. 



Order of 

tests. 



Num- 
ber of 
days in 
storage. 



Percentage of germination. 



Trade condi- 
tions. 



Envel- 
opes. 



Bottles. 



Envel- 
opes. 



Bottles. 



Basements. 



Eiivel- 



Bottles. 



Lake City, Fla . 
Do .-■ 

Auliuni, Ala . .. 
Do 

Mobile Ala 

Do 



Baton Rouge, La. 
Do 



San .Juan, P. K 
Do 



Wagoner, lud. T. 
Do 



Durliam, N. H ... 
Do 

Ann .Vrbor, Mi<-li 
Do 



First.... 
Second . 

First 

Second . 

First 

Second . 

First 

Second . 

First.... 
Second . 

First.... 
Second . 

First 

Second . 

First.... 
Second . 



129 
234 

102 

275 

110 
2ti2 

121 
247 



12tl 
238 

147 
251 



98 
92 

94 

80 

98 
64 

100 
92 

90 

88 

98 
94 

98 
82 

100 
96 



Average percentage of ger- (First 

mination. (Second . 



Average i>ecentage of h 
in vitality. 



128 
251 



97. 75 
86. 75 



(First... 
Iseeoud 



128 
251 



0.56 
12. 37 



98 
96. 2 

94 
100 

98 
96 

98 
98 

100 
100 

98 
98 
98 
9(! 

100 
100 



98 
98 

98 
98 

100 
96 

100 
100 



100 
94 

100 
96 

100 
100 

98 
100 



100 

98 

94 
96 



100 
96 



96 

88 

98 
94.1 

98 
100 



98 
98. 02 



96. 86 
88.67 



98. 29 
9(i 



95. 29 
77.70 



98. 29 
97.43 



0.31 
0.99 



1.47 
10.44 



0.01 
3.03 



3.06 

21.52 



0.01 
1.59 



What has been said of the tomato seed is practically true for the 
watermelon, save that there was a greater loss in vitality in the latter, 
when seeds were kept in envelopes. The average percentage of ger- 
mination of the second tests was 86.75 per cent for trade conditions; 
S8.67 per cent for dry rooms; and 77.7 per cent for basements, or a 
loss in vitality of 12.37, 10.44 and 21.52 percent, respectively, as com- 
pared with tlie vitality of the control sample, which germinated 99 
per cent. 

An examination of the foregoing set of tables will show that in 
most cases the deterioration was comparatively slight during the first 
128 days. Yet even during this short period the losses in vitality 
were veiy marked in some of the more critical localities, particularly 



COMPARISON (>K METHODS OF STOlUNG AND SHIPPING. 



(^3 



vA l\I()l)ilo. Ilowi^vcr, the urctitrst loss, as show n hy the ocrmiiiatioii 
tests, was durino- the VSd days iimiiediatcly t'ollowiiii;-. 

While seeds, like other living- thinos, are capable of withstanditio- 
(piite unfavorable condilions for a consideral)le time without showiuo- 
any apprecial)lo deterioration in vitality, still the forces destroying 
vitality are at work. When the turning' point is once reached and can 
be detected by germination tests, the decline is more noticeable and 
death soon follows. 

The preceding tables show that the loss in vitality was very diti'er- 
ent in the diti'erent places. The conditions at Mobile, Ala., i)roved to 
be the most injurious, while those at Ann Arbor, Mich., were the 
most conducive to longevity. These results, however, are given in 
another part of this paper dealing with the etl'ect of clim;ite on the 
vitality of seeds. The r(^.svdts are tabulated on i)ages iS and )i>) and 
represented diagraumiatically on page 24, so th:it any further discus- 
sion at this time is unnecessary. 

Likewise each table has been summarized, giving the average per- 
centages of germination and the average percentages of the loss in 
vitalitv of each sample of seed for both the first and second tests. 
These averages include those of the three conditions of storage — trade 
conditions, dry rooms, and l)asements — in l)oth envelopes and Ixjttles. 

Naturally, the results of the second tests ai'c of the greater impor- 
tance, and, in order that the results may be readily compared and more 
critically examined, th(\v have been collected and tabulated herewith: 

Table XXV. — ArirtKjc iK'vcc)it(((jf <if (jcriniiialiuu cmd artrdt/i' pcrcfiilat/fs of loss i.n 
ntalilji of I he differed Av"iif/.s of seeds ivheii kept, under different (■(ind'dions. 



Kiud of .sL'cii. 



Toninto 

Sweet t'oni, "A" , 



W.-itoriiiolon 

Lettuce 

Kaclisli 

SwiH't cdrn, "B" 

Bean 

('al)b:iKe 

Carrot , 

Onion 

Pan.sy 

Phlox 



Average loss 
in vitalitv 



Trade conditions. 



Knvclopes. Bottles. 



O 

'J'2. 11 
.S3 

M. 74 
SO. 7.5 
77. 7.5 
00.94 
05. 41 
69. .50 
52. 15 
37. 31 
25.12 

,s 



31 

75 
25 
02 
12 1 
56 6. 
70 32 
1, 

.5o: 1. 

87 1. 

2,5' 1. 

J 
75 15. 

I 
37 +(s. 



Dry rooms 



Envelopes. Bottles. 



o 



94. 33 
83.33 
80.45 
88. 67 
78. 33 
64. 33 
66.33 
69. 33 
61. 50 
63.83 
61 

24.41 
17.91 



3.29 
9.81 
15. 94 
10.44 
16.14 
18.37 
25.06 
29. 76 
33.44 
34.35 
37.12 
53. 97 
66. 78 



0.44 
+ 2.06 
. 58 
3.03 
1.49 
7.73 

45. 76 
1.36 
2.07 
S. 89 
4.80 

23. 02 
7.91 



Basements. 



Envelopes. 



O 



84. 25 
73.08 
60. 66 
77.70 
05. 58 
59 

00. 41 
55. 66 
53. 33 
37 
38. 08 
8.08 
11.08 



30. (12 
21.. 52 
28. 95 
25. 13 
31.74 
43. (il 
42. 29 
.53. 96 
05. 90 
84. 76 
79. 45 



Bottles. 



98 
90. 28 

97. 43 
90. 78 
74. 07 
08. 40 

98. m 
92. 21 
75. 21 
90. 8(; 
38. 43 
.59. 50 



0.30 

- 6.06 

^ . 00 
1.59 

1.05 



22. 71 

+ .10 

. 22 

9. .50 

0. 33 

27. 49 

-10.39 



64 thp: vitality and germination of seeds. 

In coiiiparino- the iiverag-e resultts .shown in Tuble XXV, it will bo 
seen thiit ditt'crcnt seeds behave very dili'erentlv under practically iden- 
tical conditions. The list of seeds has been arranued according- to 
their loss of vitality as represented ])y those kept in envelopes under 
trade conditions, as shown in the fourth column. The tomato seed 
gave a loss in vitality of 5.20 per cent, l)eing the most resistant to the 
unfavorable climatic conditions. Phlox, on the other hand, germinated 
only 7.(32 per cent, representing a loss in vitality of 85.86 per cent. 

Likewise the same seeds behave ver}' ditierently under slightly 
different conditions, as will be seen by comparing the j)ercentages of 
deterioration in the case of seeds kept in envelopes under trade condi- 
tions, in dry rooms, and in basements. In dry rooms the order, except 
the peas, is the same as for trade conditions. The loss of vitality in 
the seeds stored in the dry rooms was uniforndy less than for those 
stored under trade conditions, excepting for the peas and beans; l)iit 
in the series from the l)asements there was great irrcgidarity. The 
loss in vitality for the most part was uniforndy greater than under 
trade conditions or in dry rooms save in the last live — ca))bage, carrot, 
onion, pansy, and phlox — where the loss was less in the case of those 
kei)t in the basements. This indicates that these live s})ecies of seed 
are less suscepti])le to the evil eli'ects of a moist atmosphere when the 
temperature is relatively low. 

The relative value of these three conditions for storing seeds in 
paper packets is best o])tained by a c()m[)arison of the general averages. 
The average losses in vitally for the thirteen ditferent samples of seed 
which were kept at the eight ditierent stations were as follows: Trade 
conditions, ;5().(!3 per cent; dry rooms, 21.11> per cent; l)asements, 41^.28 
per cent. From these results it is (|uite clear that seeds put up in paper 
packages will retain their vitality much better if kept in dry, artilicially 
heated rooms than if they are sul)jected to trade conditions or stored 
in basements. 

But another comparison needs yet to be made, and is the most impor- 
tant of the series, i. e., the vitality of seeds when kept in closely 
corked bottles. In the majority of cases there was ])ut little deviation 
from the control samples, and many of the samples germinated even 
better where the seeds were kept in bottles. The " xi "sweet corn 
oU'ers the best illustration of the increased gerndnation. At the same 
time the " B" sample of sweet corn was very much injured. Here are 
two samples of the same variety of corn behaving very ditierently 
when kept in bottles. This difl'erence in vitality is directly attributed 
to the greater (piantity of water in sample '' B," showing the necessity 
of thoroughly drying seeds if they are to be put u}) in closed vessels. 
A comparison of the general averages of the bottle samples and of 
those kept in envelopes indicates that the former is far superior to the 
latter as a method for prescrNing the vitality of seeds. Under trade 
conditions the loss in vitality was 80.63 per cent in envelopes and 



EXPERIMENTS IN KEEl'lNG AND HHIPriNG. 65 

3.J»8 per cent in bottlos; in dry rooms, 21. H» percent in envelopes unci 
S.(»s p(>r cent in bottU^s; in Imseiiionts, -1:2. 2S per cent in envelopes 
and 4. 51 per cent in bottles. 

The necessary precautions to be taken, if seeds arc to be stored in 
bottles, are (1) a well-dried sample, preferal^ly ai'titicially dried seed, 
and (2) a cool place for storino-, at least a place in which the tempera- 
ture will not be liig-her than the temperature at which the seeds were 
orig-inally dried. 

If the aljove precautions arc taken at least two beneficial I'esults will 
follow: First, protection against moisture, which is of considerable 
importance, as man}^ seeds are soon destroyed in that way when kept 
in paper packages. Secondly, vitality will })e preserved for a longer 
period and conse([uently there will be a more vigorous germination, a 
better growth of seedlings, and a greater uniformity in the resulting 
crop. 

Having thus shown that seeds retain their \'itality in warm, moist 
climates nuu-h 1 tetter when kept in bottles than when kept in paper 
packages, the necessity of finding a more suitable method for sending 
small (juantities of seed to such places at once presents itself. 

EXPERIMENTS IN KEEPING AND SHIPPING SEEDS IN 
SPECIAL PACKAGES. 

At present the greatest disadvantages in sending out seeds in bottles 
are the inconvenicMice and expense involved ))y this method of putting 
up seeds. The increased cost of ])ottles, as compared with the paper 
packets now so universally emplo3"ed, the additional la))or and expense 
necessary to put up the seeds, the greater cost in handling- and pack- 
ing the bottles to insui'c against losses by l)reakagc, and the increased 
cost of ti'ansportation, are all matters of vital imjxtrtance. Seedsmen 
claim that the existing conditions of the trade will not admit of their 
raising the price of seeds sufficiently high to justify the increased 
expense of glass containers. Although to the seedsmen the preserva- 
tion or the prolongation of vitality is an important factor, yet the 
demand is for an inexpensive and at the same time a neat and service- 
able package. 

Accordingly, duplicate samples of the following-named seeds were 
put up in special packages, one set being sent to Mobile, Ala., and the 
other kept at Ann Arbor, Mich. The seeds used for these experi- 
ments were beans, peas, cabbage, lettuce, onion, pans}', and phlox." 

«The lettuce, onion, pansy, and phlox were from the game bulk samples of seeds 
as those used in the earlier experiments; but the beans, peas, and calibage used for 
these tests were from samples received at the laboratory on February 4, 1901. How- 
ever, the latter three were from the same general stock of seed, differing from those 
used in exi^eriments already given only in that they were stored during the interval 
in the warehouse of D. M. Ferry & Co., Detroit, Mich., instead of in the botanical 
laboratory at the university. 
25037— No. 58—04 5 



66 



THE VITALITY AND GERMINATION OF SEEDS. 



All of those samples were first dried for ten days in an iiicu])ator main- 
tained at a temperature of from 30 to 32 " C. The amount of mois- 
ture in the samples before and after clryinji;-, as well as the moisture 
expelled during the drying- process, Avas as follows: 

3Ioiiitvrc test of needs In sprrkil p<icJ:a(jes. 



Kind of seed. 



Bcaus . . 

Peas 

Cabbage 
Lcttuee. 
Onion . . 
Pansy . . 
Phlox . . 



Moistnre in 
alr-flried 

samples. 



Per cent. 
10. 32 
9.70 
4.S9 
5.33 
C. 48 
•1. S2 
5. 82 



Moisture 
remaining. 



Per cent. 
4.90 
6. 00 
3.47 
3. 80 
4.47 
3.13 
4.30 



Moisture 
liberated. 



Per cent. 
5.42 
3.70 
1.42 
1.53 
2.01 
1.69 
1.52 



These well-dried seeds Avere then put up in seven different kinds of 
packages : 

(1) Double coin envelopes, of niiu-h the same ({uality as those in which 
seeds are commonly sold. 

(2) Bottles of 120 cc. capacity, closed with firm covk stoppers. ! 

(3) Bottles of 120 cc. capacity, corked and sealed with paraffin. 

(4) Tin cans having closely fitting lids, the whole being then care- 
fully dipped in paraffin. 

(5) Double coin envelopes, as for No. 1, the packets l)eing then 
dipped in melted paraffin. 

(()) Double coin envelopes, the inner one paraffined, the outer envel- 
ope being used simply to protect the paraffin and to facilitate ease of 
handling. 

(7) Double coin envelopes, with t)oth the inner and the outer coated 
with paraffin. 

On February 15, ll»()l, one of each of the above preparations was sent 
to Mobile, Ala., and stored in a cellar approximately -400 feet l)ack 
from the bay. After the lapse of 108 days, i. e., on June 3, these 
samples were received in return, at which time germination tests were 
made. 

The otiier complete set, retained in the ])otanical laboratory at Ann 
Arbor, was subjected to a veiy moist atmosphere. The samples were 
kept in a damp chamber made by taking two battery jars of different 
sizes, the smaller containing the seeds being placed within the larger, 
whicli was lined with filter paper and then partially filled with water. 
The whole was covered with a glass plate, and the atmosphere w^ithin 
was always on the verge of saturation. 

A third and an extreme set of conditions was established b}^ keeping 
some of the paraffined psickages immersed in water for twentj-seven 



expp:rim.p:nts tn k?:eplng and sini'i'iNd. (57 

days. At tlic ciul of that time (Marcli l-t) the seeds wei-e tested for 
genuuiation, as were also those from the unprotected eiivel()]X's in 
the moist chandler. The seeds that were kept luuU'r water in the 
paraiiined packag-es germinated readily and normally, showing- no 
deterioration in vitality; but the seeds from the packages not paraffined, 
which Avere kept in the moist chanil)er, had been injured to an appre- 
ciable extent, there being a marked retardation in the germination of 
all of the species of seed. The cabbage at the end of thirty-six hours 
had germinated only 11 per cent, as compared with 5T.5 per cent for 
seed froiu the immersed paraffined package, Th(^ rcdative merits of 
the two conditions as ati'ecting onion seed may ])e expressed b>' a 
germination of 13.5 per ceut and 89 per cent, respectively, after sixty- 
one and one-half hours. Not only Avas there a marked retardation, 
but likewise a reduction in the final percentage of germination, with 
the single exception of the cabbage. These results can be more care- 
fully studied in Tahle XX Vi. 

Germination tests were made of all of the other samples on .Tune 3, 
1901. the date when the seeds were returned from iNIohile. At this time 
the seeds in the luiprotected envelopes in the moist chanil)er were so 
badly molded that no germination tests wore made. Tlu^ samples from 
Mol)ile, wdiich were directly comparal^le with the al)ove, except that 
thev had been stored in a l)asement, were greatly injured. The l)eans 
had deteriorated to 88 per cent, the onion to 27 per cent, the pansy to 
8 per cent, while the phlox was dead. However, se(>d of the other 
species — cabbage, lettuce, and peas — gave final p(^rcentages of germi- 
nation varying but little from the control, l)ut the slowing down in 
the rapidity of germination was sufficiently marked to show a corre- 
sponding loss in vitality. 

With the samples which were i)ut up in bottles, tin cans, and 
paraffined packages the results were quite difierent from those given 
al)ove. In no case was there any marked deviation beyond that which 
might be justly attributed to ordinary variation, except in the phlox 
from a tin can which had ))een stored in the moist chain I xu' in the 
laboratory. This sample of phlox germinated only 3.5 per ceut. 
Unfortunately, ])oth the pansy and the phlox seeds used for these 
experiments were not vei-y satisfactory. These samples wow at this 
time nearly two years old and consequently of a low vitality. The 
tabulated results of the foregoing experiment folloAV. 



68 



THE VITALITY AND GEKMINATION OF SEEDS. 



T A KLio X X \' I . — I 'ilnlltij of seeds jire 



'I in. (Jiffrrent kinds of jmckagcs. 





Dura- 
ion of 
■xperi- 
nient. 




Percent 


ige of 


germination 




Trc.'.'ituiont of Manii>l<'s. 


Beatis. 


Cab- 
bage. 


Let- 
tuce. 


On- 
ions. 


Peas. 


Pan- 
sy. 


Phlox. 


Aver- 
ages. 


Control 


Pays. 


94. 


90. 2 


89. 5 


97.5 


90. 


37.7 


42. 5 


77 34 


Ann Arbor, Midi., moist chambor: 






Envelopes 


■27 


80.0 


91.0 


70.5 


90.0 


.SS. 


25. 


0.0 


(U.35 




108 
108 
108 


98.0 
97.5 
96.0 


91.5 
93.5 
87.0 


91.0 
90.5 
90.0 


93.5 
95.5 
93.0 


91. 
90.0 
90.0 


36. 
39.5 
35. 


31.0 
39.0 
3.5 


76.43 




77.93 


Tin can, paraflined 


70. 63 


Two envelopes, outer paraflinod 


108 


98.0 


91.5 


91.5 


97.0 


92.0 


33. 5 


27. 5 


75.85 


Two envelopes, inner paratflned 


108 


98.0 


94.0 


89. 


93. 


88.0 


21.0 


47.0 


76. 14 


Two envelopes, both paraffined 


108 


96. 


90. 5 


S(i. 5 


95. 5 


92. 


23. 


38. 5 


74.57 


Two envelopes, both i>araffined and 




















immersed in water 


27 


100.0 


8.S. 5 


88.5 


91. 5 


90. 


31. 5 


30.5 


75 21 


Mobile, Ala., basement: 






108 


8.S. 


8(). 


88.0 


27.0 


96. 


8 





56.14 


Bottle, corked 


108 
lOS 
108 


98.0 
98. 
9Ci. 


91.0 
90.5 

88.0 


90.5 
92.5 
95.0 


95. 5 
95. 5 
96.0 


81.0 
92. 
88.0 


34. 5 
34.5 
26. 


32. 5 
44.5 
23.0 


75. 14 


• Bottle, paraffined 


78 21 


Tin can, paraffined 


73. 14 


Two envelopes, outer paraffined 


108 


91. 


90.5 


89. 


95.5 


92.0 


29. 5 


34.0 


74.73 


Two envelopes, inner paraffined 


108 


90. 


92.0 


88.0 


90.0 


98.0 


33.0 


38.0 


76. 43 


Two envelopes, both 7>arafflned 


108 


100.0 


92. 


89. 5 


88. 5 


90. 


25. 5 


33. 5 


74.14 



Subsequent experimentw were made, using envelopes of diiierent 
qujilities, as well as Aaiying- the treatment of the packages. Samples 
of cabbage, lettuce, and onion seed were put up as follows: 

(a) The regular seedsmen's envelope, made of a heavy grade of 
manila paper. 

(/») Envelopes made of a medium (jualit}' of Avaterproof paper. 

{(') Envelopes made of a thin i)archment i)aper. 

(d) Envelopes made of the same quality of parchment paper as for 
the preceding series, ])ut paraffined previous to ])cing tilled with seed. 
The packages were then sealed by redipping the open ends. 

(e) Envelopes of parchment paper, as for the two preceding series, 
except that the envelopes were first filled w4th seed, sealed, and then 
the entire package was dipped in paraffin at a temperature of from 
55^ to (50^ C. 

Samples of all of these packages were then stored under trade con- 
ditions and in dry rooms in Ann Arbor, Baton Rouge, and Mobile. 
The exact conditions of storage in the diii'erent places were the same 
as described on pages 49 and 50. 

The samples were put up on May 20, 1901. The period of storage 
ended on November 26, having continued 190 days. Unfortmiately, 
no special precautions were taken to dry the seeds. They were simply 
air-dried samples; lience they contained a quantity of moisture sufii- 
ciently large to give rise to an increased relative humidity of the 
confined air in the paraffined packages. This increased humidit}^ was 



EXPERIMENTS IN KEEI'ING AND SHIPPING. 



69 



accoinpimiod hy a greater activity within the cells, and con.scquently 
l)y a greater deterioration of vital force. For this reason tlu^ results 
are not as detinite as the conditions warrant. NcvertheU^ss, sonic 
ini})oi-taiit facts were brought out by the experiments which justify 
their being discussed and tabulated (in ])art) at this time. 

Taumo XX^''II. — V'lUilUii of itced prt'iiern-d In jxiruffi tied 'parka yes. 





Trade conditions, seeds put up in — 


Dry room, seeds put up in- 


Kind (if seed. 


Paraffined 
envelopes. 


Parchment 
envelopes, 
tlien dip- 
ped in par- 
affin, at 
50° to 60° C. 


Seedsmen's 
packages. 


Paraffined 
envelopes. 


Parchment 
envelopes, 
then dip- 
ped in par- 
affin, at 
50° to 00° C. 


Seedsmen's 
pacjvages. 


Cabbage: 

Ann Arbor, Mieli 

Moliile, Ahi 


Per cent. 
91 

HO. r> 

70 

.S'.t. .") 
so 

'.tl 



1 


Prr rent. 
90 

.57. 5 
(■.3 

K9. 5 

90 

i 

20 


Per rent. 

sn. 5 

H. 5 
'J"2. 5 

90. 5 

(14 
74 

93 




Prr rent. 
90. 5 

:tt 

73. 5 

91.5 

7.S 

,S'J 

91.5 

'* 


Prr cent. 
85. 5 
.50. 5 
79. 5 

90 

7S. 5 
73. 5 

S9 
4. 5 
40 


Prr rent. 
SO. 5 

35 5 


Lettuee: 

Ann Arbor, Mieli 

Mobile, Ala 


93 
fil. 5 


Baton RonK(\ La 

Onion: 

Ann Arbor, Midi 

Mobile, Ala 

Baton Ronge, La 


72. 5 

SO 






59. 39 


(V2. 94 i 49-14 1 fil.11 


65. 66 


49 22 













In the first place, the injury resulting from the effect of the climatic 
influences i.s <|uite well marked in the above table. The conditions at 
Mobile and Baton Rouge were much more detrimental to the life of 
the seeds than were the conditions at Ann Arbor. Secondly, the dif- 
ferences in the preservation of vitality of those seeds stored under 
trade conditions and of those kept in dry rooms were much less marked 
than they were in earlier experiments. This is probably accounted 
for ])y the marked dift'erence in the two seasons. The summer of 1900 
was extremely wet in the South, especially at Mobile, while the sum- 
mer of lOol was exceptionally' dry. Concerning the conditions Zim- 
mcr Brothers wrote on November 20, 1901, as follows: 

We do not tliink you will lind much difference in the two packactes. The season 
this year lias bi'en very dry, with no rain since the big August storm; in fact, we do 
not remember such a dry season in thirty years. 

Although the season was exceptionally dry at Baton Rouge and 
Mobile, the loss in vitality was very g-reat in comparison with the loss 
at Ann Arbor, demonstrating- very clearly that climatic influences play 
a very important part in the storage of seeds. 

This table shows the relative resisting powers of lettuce, cabbage, 
and onion seed, the lettuce being* most resistant and the onion least 
resistant, as shown in a preceding table. However, the chief purpose 



70 THE VITALITY AND GERMINATION OF SEEDS. 

of this series of experiments was to demonstrate tlie relati\'e value of 
ditfercnt packages as a means of putting up seeds. 

In Table XXVII it will be o))ser\ed that the results obtained from 
the waterproof and parchment paper envelopes have been omitted. 
These omissions have been made because the results were practically 
identical with those of the ordinary seedsmen's packets; ])ut the com- 
parisons to be made l)ctween the ordinary paper packets and the 
parafHned packages are worthy of consideration. The envelopes that 
were parafHned after being tilled with sc^ed gave the best results. 
This difference, however, was due not to the special treatment but 
to the higher melting point of the paraffin. The average percentages 
of germination of the three samples of seed kept under trade con- 
ditions in the three localities were 59.39 per cent for the envelopes 
previously paraffined, 62.94: per cent for the envelopes dipped in 
paraffin after being tilled with seed, and 49.44 per cent for the seeds- 
men's envelopes. In dry rooms the results were 61.1 L, 65.66, and 
49.22 per cent, respectively. These averages were somewhat higher 
than the true conditions of Baton llouge and Mobile warrant, as the 
results of tlie germination tests from all of the packages retained at 
Ann Arbor showed but little variation. Taking the three samples of 
seed wdiich were stoi'ed luider trade conditions in Mo))ile, the average 
percentage of germination was 24.2 for the seed from the nonparatlined 
package and 45. 5 per cent for the seed from the paraffined package, show- 
ing a loss in vitality of 7T.3 and 49.5 per cent, respectively, considering 
the germ ination of the Ann Arbor sample as a standard. At Baton liouge 
the results were slightly l)etter; the average percentages of germination 
were 32.2 for the seeds from the non])araffined and 53.5 per cent for 
the seeds from the paraffined packag(\s, representing a loss in vitality 
of 65 and 4<).5 per cent, respectively. While in either case the loss 
was very great, still the advantages of the paraffincnl packages arc 
worthy of consideration for the reason that a prolongation of life for 
only a few wrecks is f recjuently of the greatest importance, particularly 
in districts where nmch fall planting is done. 

In this connection may be given the results of some other tests, 
which reall}" were a part of this same experiment, but included only 
onion seed. This seed was put up in seedsmen's envelopes and in 
paraffined envelopes like those pri^viously described. In addition, 
seed was also put up in small bottles, which were corked. These 
packages were kept in a small l)ox within a suit case carri(>d on two 
trips across the Atlantic and on a tour through Central Europe, thus 
subjecting them to yery variable conditions. Germination tests 
gave the following results: Seed from the ordinarj- packages, 77 per 
cent; paraffined envelopes, 90 per cent; bottles, 91 per cent. 

To test more thoroughly the keeping qualities of seeds in paraffined 
packages and in l)ottles, another series of experiments was begun on 
Deceml)er 20, 1901. For these tests oidy cabbage and onion seeds 



p:xperiments in keei'in(} and snirriNo. 



71 



were u.sed, but each with thi'ce different deo-recs of moisture: (1) Seed 
from the orioinid packaoe.s, i, e., air-dried samples, the cabbage hav- 
ing a water content of 5.80 per cent, and the onion G.48 per cent. 
(2) Air-dried samples were exposed in a moist atmosphere under a bell 
jar for two days, during which time the cabbage absorbed 1.83 per 
cent of water and the onion 2.11 per cent, thus raising the water con- 
tent to T.<)o and 8.80 per cent, respectively. (3) Air-dried seeds 
which were dried in an incu])ator for eight days at a temperature vary- 
ing f i-om 27 C to :]',» C. During this interval 2.0,5 per cent of water 
was expelled from the caljbage and 3.11 per cent from the onion seed, 
leaving a water content of onlv 3.75 per cent in the former and 3.37 
per cent in the latter. 

Each of the samples, treated as just descril)ed, was put up in three 
different kinds of packages: (1) Seedsmen's regular seed envelopes. 
(2) Similar envelopes which were paraffined, after being filled with 
seed, at a temperature of from 70'^ to 75° C. The melting point of the 
paraffin was 53'^ C. (3) In bottles which were closed with firm cork 
stoppers. 

One of each of the above packages was then stored at Mobile under 
trade conditions and in a basement; likewise at Ann Arbor in the 
herl)arium room of the l)otanical la])oratory, in a greenhouse, and in 
an incubator maintained at 40° C. The duration of this experiment 
was 131 days, from Deceml)er 20, 1!>(>1, to Api-il 30, 1!»02. The results 
of the germination tests are given in Tal)le XXVIII. Two percentages 
have been given for the control sample, one for Ann Arbor and the 
other for Mo})ile. This was necessary since the two series were tested 
at different times and comparisons can not be made interchangeably 
between the two. 



Tahle XXVTTI. — Yitfirily of caJihage avd onion seed rr.v prcsrrvcd iv. vdrloiis k'liids of 
]i(ifka(/e.^ itnd xidijecfcd fo diffcrml eondltioiix of slorcKjc. 

[Genniiuitiim (if cdiitrol .'^ample.s— Ann Ar))()r: (_:abbagt', 81.7 per cent; onion, 74 per cent. Jlobilo: 
Cabbage, 88 i)cr cent; onion, 81.5 per eent.] 





Speoial treat- 
ment of 
package. 


Percent- 
age of 
water 
content 
of seed. 


Percentage of germination. 


Kind of seed and 


Ann Arbor, Mich. 


Mobile, Ala. 


package. 


Botan- 
ical 
labo- 
ratory. 


Tra.le 
condi- 
tion.s. 


(Jreen- 
hou.se. 


Incuba- 
tor at 

40° C. 


Trade 
condi- 
tions. 


Base- 
ment. 


Cabbage: 

Enveloj)c 


None 


5.8^ 
5. 8U 
5. 80 
7. 63 
7. 63 


81. 
80.0 
79. 5 
85. 5 
SO. 5 


81 . 
79.0 
85. 
80. 5 
82. 
85.0 
85. 5 
84. 
84. 


68.0 

85. 5 
S5. 
()5. 5 
83. 5 

86. 5 
67.0 
76.0 
74.0 


72. 5 
62. 
68. 5 
74.5 
69.5 
48.0 
73.0 
71.0 
64.5 


60. 
87. 5 
81. 
64.5 
86.5 
82.0 
64.0 
82. 5 
82.5 


10 


Do 


Paraffin 

f forked 


52. 5 


Bottle 


84. 


Envelope 


1.5.5 


Do 


Paraffin 

Corked 


46 5 


Bottle 


7.63 80.5 
3.75 76.0 
3.75 i 86.0 
3.75 1 83.0 


91.5 


Envelope 

Do 


9.0 


Paraffin 

Corked 


78.0 


Bottle 


85.0 



72 



THE VITALITY AND GERMINATION OF SEEDS. 



Table XXVIII. — VltalUn of cahhar/r and onion seed as preserved i)i various ki^ids of 
packa(/es and snhjected to different kinds of storage — Continued. 





Special treat- 
ment of 
package. 


Percent- 
age of 
water 
content 
of .Mced. 


Percentage of germinatien. 




Ann Arbor, Mich. 


Mobile, Ala. 


jiiickagf. 


Botan- 
ical 
labo- 
ratory. 


Trade 
condi- 
tions. 


Green- 
house. 


In(nil)a- 
tor at 
40° C. 


Trade 
condi- 
tions. 


Ba.se- 
ment. 


Onion: 


None 


G. 48 
G. 4S 
f>. 4.S 
8.89 
8. 89 
8. 89 
3.37 
3.37 
3.37 


78.5 
7f). 5 

73. .5 

74. 5 
74. 'i 
78.0 
Gl. 5 
75.5 
76.5 


(i9. 5 
OG. 5 
71.5 
fiO.O 
GG. 
GS. 
G3. 5 
72.5 
71.0 


3.5 

67.0 
60.0 
11.5 
50. 
67.5 
8.5 
58.0 
77.0 


47.0 

4.5 

Gl.O 

28.0 

9.0 

3.0 

•> G.O 

? 9.0 

59. 5 


19.5 
83.0 
8G.0 
21.0 
74.5 
77.5 
17.0 
77.0 
84.5 


10.0 


Do 


Paraffin 

Corked 

None 


27.0 


Bottle 


82.5 




2 5 


Do . . 


Paraffin 

Corked 

None 


21 


Bottle 


78.5 


Envelope 


G 


Do 

Bottle 


Paraffin 

Corked 


CO. 5 
81.5 









Many of the points ln-ought out l)y this tabic are veiy simihir to 
those of the preceding- one, 3'ct the ditierences are sutticiently marked 
to justify its being given in this connection. The seeds stored in the 
botanical laboratory and those subjected to trade conditions at Ann 
Arbor have g-erniinated practically the same, the cabbage slightly 
favoring trade conditions and the onion being better' preserved in the 
laboratory. But a comparison of the tra<le conditions at Ann Arbor 
and Mobile in the unprotected packages shows the same wide variation 
that has been alread}- pointed out. 

The advantage of drying is not very clearly brought out in this 
table; in many cases there seems to have 1)een a slight injury as a 
result of the high temperature at which the diying was done. Una- 
voidably the temperature at that time reached 39° C, which, as has 
already been stated, is slightly above the maximum to wliich seeds 
can be su])jected for any considerable time without injury. The 
injury due to heat is very evident in the samples stored in the incu- 
bator maintained at iO" C, this injur}' Ijeing more apparent with the 
increased moisture, especially in the paraffined package and in the 
bottle. However, on the whole the percentages of germination are 
higher for the dried seed than for the seed which had al)Sorbed an 
additional ({uantity of moisture; and, indeed, the comparison should 
properly be made with these two, for seeds as they are usually stored 
contain even higher percentages of moisture than either the cal>bagc 
or lettuce after they had absor])ed tile additional amount of water. 

But the chief purpose of the present experiments was to determine 
the relative advantages of envelopes, paraffined packages, and ])ottles 
as methods of putting up seed in order that vitality might l)e pre- 
served for a longer time. This comparison is best made l)y consider- 



exi>p:rtmknts in Kp:EriNG and SHirriNG. 



78 



int^i' the vitality of the seed stored in the greenhouse at Ann Arbor and 
luicU'r trade eonditious at Mo])ile. It will he readily seen that the 
vitality of the seed from the unprotected packages was greatly reduced, 
while those from the paraflined envelopes and from the bottles germi- 
nated nearly as well as the controls. These difi'erences are bottei' rep- 
resented diagrainmatieally, as follo^vs: 

J>i(ii/rniii n jircuf'iiliiiij IIk' prrcciilnt/ca of (/irni'mation of cdhbttgc Kccd irJic^i Irralnl rifs 

dcsrrllx'd. 



Kind of 
package. 


Special treat- 
ment of 
package. 


Percent- 
age of 
water 

content 

of seeds. 


Ann Arl)or, Mich., green- 
hou.se. 


Mobile, Ala., trade 
conditions. 






5. so 
fi. so 
5. so 
7. (« 

7. (;:> 
7. <;:! 
8. 7r> 

•i. 75 

3. 7ri 

5. SO 


78. 3 


00 






Do 


raralliiicd 

Corked 


92. 1 


s7. ."> 


Bottle 


91.. ") s) 


P^nveloiir 


70. 5 


(i-t ."i 




Paraflinetl 

(forked 




Do 


SO. '.» 








Bottle 


93 1 


S'> 






Envelope 


7'i 1 I rA 




I'arafliiied 

Corked 

Original pack- 
age. 




II 


r)o 


Sl.S 


S-' .S 






Bottle 


79.7 








Control sample . 


ss 


SS 









DUigntni rrpresenling the pcrcenUigcs^ of germinal ion of ouion seed tvhen ircided as described. 



Kind of Special treat- 


Percent- 
age of 
water 
content 
of seeds. 


.\nn Arbor, Midi., green- 
hoii.se. 


Mobile, Ala., trade 
conditions. 


Envelope - 


(i. 48 
0. fS 

C. IS 

s. S9 
S. so 
s. S9 
3.37 
3.37 
3. 37 
(!. 4S 


4 

7f.. r. 


10 s 


Do .. ... 




S3 




Corked 




Bottle 


('iS. i\ 








Envelope 


13. ■! 
04 


•)] 


Do Paraflined.... 


74.. "> 


Bottle 


Corked 


77. 3 








Envelope 


9.7 
00. 3 


17 


Do 


Paraflined 

Corked 

Original iiack- 
age. 






' ' 


Bottle 


ss 








Control sample.. 


S4..'-. 


s4.ri 









The percentages for Ann Arbor shown in the graphic representations 
are not the same as those given in the foregoing- table. In the diagram 
they are directly c<)mparal)le with the results from the Mobile series, 



74 THE VITALITY AND GERMINATION OF REEDS. 

all beino- based on the vitality of the controls, as shown ])y the tests 
made at that time, the standard being- 88 per cent for the cal:»bag-e and 
84:. 5 per cent for the onion. 

A discussion here hardly seems necessary, as there can l)e no doubt 
that seeds retain their vitality nuich better in moist climates if pro- 
tected from the action of the atmosphere. This ma}^ be accomplished 
by dipping" the packages in paraffin or ]>y putting the seed in bottles. 
Disregarding the expense, bottles surpass paraffined envelopes as a 
means for the preservation of vitality, and also in tlu^ ease with which 
the seed can be put up. The results are more certain if care is exer- 
cised in selecting good corks. 

RESPIRATION OF SEEDS. 

I'rom a practical point of view it has been conclusively sliown that 
moisture is the controlling factor in seed life. Seeds stored in a 
humid atmosphere soon lose their vitality, 1)ut if carefulb: dried and 
protected from moisture life is greatly prolonged. 

The question at once presents itself: In what Avaydoes the presence 
of increased ({uantities of moisture . cause a premature death of the 
seed, or why is vitality prolonged if the water content of the seed be 
reduced? 

In a measure, the answer to this question is re.'<piratl<»i. Seeds as 
we commonly know them absorl) oxygen and give oft' carbon dioxid; 
that is, respire." During their respiratory activities the energy 
stored within the seed is readily evolved, the vital processes are 
destroyed, and life becomes extinct. The intensity with which respi- 
ration takes place is largely dependent upon the lunnidity of the sur- 
rounding atmosphere, wdiich idtimately resolves itself into the amount 
of water in the seed. The respiratory activity is directly propor- 
tional to the quantity of moisture al)sorbed b}^ the seed up to a certain 
point, attaining its maximum during the process of germination. It 
has been found that a decrease in the water content results in a cor- 
responding diminution in the intensit}^ of respiration and consecjuently 
in a prolongation of the life of the seed as such. 

Bonnier and Mangin'' WiU'e the first to show that respiration in liv- 
ing plants increases with an increase in the humidity in the surround- 
ing air. As this is true for growing plants, it is even more marked 
in stored seeds. Maquenne'' suggested that a reduction in moisture 
is accompanied by a reduction in respiration, but at that time no 
experiments had been made to show that such was actually the case. 

«Kolkwitz (Ber. d. deiitsch. Bot. Ges., 19: 285-287, 1901) reports respiration in 
lecently ground seeds. 

6 Ann. sc. nat. bot., ser. 7, 2: 365-.3S0, 1885. 
cAnn. Agron., 26: 321-332, 1900. 



RESPIRATION OF SP:EDS. 



75 



In 1832, Aug-. Pvr. Do Caudollc wrote in tho second volume of his 
rhysiologie Vegetale that the vitality of seeds would be prolonged if 
they were ])uried sufHciently deep in tho soil to protect them from 
oxygen (or air) and moisture. Unfortunately, l)e CandoUe did not 
discover the true cause of this prolonged life, for nowhere did he 
make an}' reference to respiration. Nevertheless his general conclu- 
sions were properly drawn. De Candolle also stated that light acceler- 
ates evaporation in s(mh1s and thus causes a premature death. Here, 
however, his i-esults were wrongfully interpr(»te(l. These conclusions 
are applical)l(^ only in case of seeds that die if allowed to ])ecome dry. 
The real etfect of light is to cause a slightly accelerated respiration 
and conse(iuently a greater deterioration in vitalit}'. Jodin" states 
that light accelerates respiration to a markt'd degree. His experi- 
ments were with peas which contained 10 to 12 per cent of moisture. 
Two samples of peas were placed, each under a bell jar, over mer- 
cury. One sample was kept in the light and the other in the dark. 
At the end of 1 3'ears months and 11 days an analysis of the con- 
fined air from the sample kept in the light gave the following results: 

Peas, 8.452 grams, in air, iii light: Percent. 

Oxygen 19. 1 

Nitrogen - "<^- ^> 

Carl)on dioxid 1-2 

At the end of 1 years 7 months and 11 days an analysis of a sam- 
ple of air taken from the other chamber wiis as follows: 

Peas, :!.580 gramf<, in air^ in dark: Percent. 

Oxygen. 20. 8 

Nitnjgen - 79. 1 

Carl)on dioxid ^ 

The ;-].152 grams of peas that were subjected to tin* influence of the 
action of light had al^sorbed, in the given time, 2.1 cc. of oxygen and 
produced 1.8 cc. of carbon dioxid. The seed kept in the dark showed 
))ut little signs of respiratory activity. Germination tests of the 
former showed the peas to be dead, while five peas from the sample 
kept in the dark germinated perfectly. 

While there is no question that light exerts some influence on respi- 
ration, .still the above results do not furnish sullicient data to establish 
the fact that respiration practically ceases in the absence of light. In 
fact, experiments have shown that respiration is also quite marked in 
ca.se of seeds stored in the dark, and the difference is very slight if the 
same temperature be maintained. 

Van Tieghem and Bonnier, in their "Recherches sur la vie latente 
des graines,"'' demonstrated that 7.97(3 grams of peas, sealed, in air, 

«Ann. Agron., 23: 433-471, 1897. 

6 Bui. Soc. bot. France, 29: 25-29, 1882. 



76 THE VITALITY AND fnORMINATION OF SEEDS. 

in a tube, re.spirod quite freely. After the lapse of two years an 
analysis of the eontined air yave the followino- results: 

I'cr cunt. 

Oxygen 14. 44 

Nitrogen 81 . 74 

Carbon ilioxid 3. 82 

These same seeds germinated 45 per cent and had increased fi u of 
their original weight. 

In the experiments of the writer it was found that 40.1150 grams of 
air-dried beans liberated 7.7 cc. of carbon dioxid in 370 da^'s. The 
concentration of the carl)on dioxid in the flask at the time the gas was 
drawn for analysis was 1.54 per cent. This sample of seed germinated 
97 per cent, and there was only a very slight retardation in germina- 
tion, which indicated that the vitalit}' had not been materially reduced. 
During this time there was a slight decrease in the weight of the seed — 
0.19 per cent. At the same time two check bottles were set up, one 
containing 40.1184 grams of beans known to be dead, and the other 
bottle containing nothing except air. Analyses of the air from these 
two bottles gave the same results as samples of aii- drawni from the 
laboratory. These preparations were kept in subdued light through- 
out the experiment. 

That respiration may take place in the dark, that it is very intense 
if much moisture ])e present, and that intensive respiration is accom- 
panied b}' a rapid loss in vitality is shown by the following experi- 
ments. On April 3, 1900, samples of beans, cabbage, carrot, lettuce, 
and onion were sealed, each in bottles of 250 cc. capacity, and were 
stored in a dark room which was maintained at a temperature of from 
20^ to 25° C. These samples were first carefully weighed and then 
placed in a damp cham))cr for 175 hours, so that an additional ([uantity 
of moisture could be absorbed. 

Control samples of air-dried seeds were also kept in sealed l)ottles 
and subjected to the same subsequent treatment. After the lapse of 
one year analyses of the coniined gases and germination tests of the 
seeds were made, the results of which are given with the general 
details. 

BeauH. — Of beans, 24.9994 grams absorbed 4.70 per cent of water 
while in the damp chamber. The respiration during the year was 
equivalent to 2.5 cc. of carbon dioxid. The loss in weight was only 
0.05 per cent, but the vitality had fallen from 100 to SO per cent, as 
shown by the control. 

C(d>h<i(/>'. — Of cabbage seed, 10 grams, with an additional 9.79 per 
cent of water, were used for this test. During the A^ear this sample 
of cabbage seed had given off 24 cc. of carbon dioxid, an equivalent of 
2.4 cc. of carl)on dioxid per gram of seed per year. The control 
sample germinated S9 per cent, l>ut this seed w^as dead. 



KESriKATION OF SEP^DS. 77 

Ciirrot. — Of ciiiTot seed, lU omnis Avcrc iillowed to !il)sorl) during 
lTr> hours an additional 10.25 per cent of water. In one year 27 cc. of 
carl)on dioxid were i)roduced, o-iyino- a concentration of carbon dioxid 
of nearl}" 12 per cent. The deterioration in vitalit}" was from S-1 to 
per cent, as compared witli tlie control. 

Lettuce- — Of air-dried lettuce seed, 10 f^rams were allowed to absorb 
an additional S.ST ])er cent of water. During' the experiment 19.5 cc. 
of car])on dioxid were formed, an equivalent of approximately 10 per 
cent of the original volume of the inclosed air. These seeds Avere all 
killed. The control sample germinated 04 per cent. 

On! oil. — Of air-dried onion seed, 10 grams were allowed to absorb 
an additional 10.11 per cent of water. The seed gave off 2B.5 cc. of 
carbon dioxid during the experiment and deteriorated in vitalit}" from 
97 to per cent. 

A bottle containing -t cc. of water was also sealed at the same time 
and served as a check for the other analyses. A sample of air taken 
from this bottle gave the same results as the original air sample. 

It is a matter of much regret that no analyses could be made of the 
air from the bottles which contained the check samples. These bottles 
contained the same weight of air-dried seeds as was used for the 
experiments. Unfortunately the seals on these bottles had become 
dry and admitted of an exchange of gases, so that the results were not 
reliable. 

Another series of experiments consisted in keeping onion seeds in 
sealed bottles for 1 year and 13 days, with the following results: 

{(i) Fifty grams of air-dried seed were sealed, in air, in a bottle of 
500 cc. capacity. There was an increase in the weight of the seeds of 
0.1091 gram — slightly more than 0,2 per cent. An analysis of the 
inclosed gas gave: 

Pit cunt. 

Oxygen 12. 27 

Nitrogen 8.5. 87 

Carbon dioxid 1. 86 

ilj) Fifty grams of air-dried seed were sealed, in air, in a 500 cc. 
bottle, with -1 cc. of water in a small test tube at the bottom of the 
l)ottle. Nearly all of the water was a})sorbed by the seeds, there 
being an increase in weight of 3.(3475 grams, or 7.3 per cent. The 
composition of the inclosed air was: 

Per cent. 

Oxygen None 

Nitrogen 86. 65 

Carbon dioxid 13. 35 

The oxygen had all ])een consumed and the seeds were all dead. 

(<") Fift}^ grams of onion seed were sealed in a 500 cc. bottle, in a 



78 THE VITALITY AND GERMINATION OF SEEDS. 

mixture of illiiniiii:itiiii>- yas and air. The iuerease in weight was only 
0.04 per cent. An analysis of the inclosed g-as was as follows: 

Per cent. 

Oxygen 3. 23 

Car])on dioxid - . . . . 1. 21 

Methane and nitrogen - - - 95. 96 

{d) Another 50-grain sample of onion seed, belonging to a different 
series, was scaled in a l)ottle of 300 cc. capacity, and showed the 
following- composition of the inclosed air: 

Per cent. 
Oxygen 8. 02 

Nitrogen ;. 85. 17 

Carbon dioxid - 6. 81 

In only one case Avas there any deterioration in vitality, namely, 
where the large quantit}' of moisture was present. The other samples 
germinated normally. The seed kept in the illuminating gas germi- 
nated even better than the control. 

In all of the bottles there was a marked decrease in pressure, show- 
ing that the volume of oxygen absorbed was much greater than the 
volume of the carbon dioxid given off. 

During respiration certain chemical changes must be taking place 
which exert a marked influence on the vitality of seeds. What these 
changes are is a (juestion yet to be solved. The protoplasts of the 
individual cells gradually but surely become disorganized. C Do 
Candolle" takes the view, in discussing the experiments of Van Tieg- 
hem and Bonnier, that during respiration life is simply subdued. 
But the period of subdued activity, he nays, is comparatively short, 
for respiration soon ceases and life becomes wholl}^ latent. As a result 
of his own experiments in storing seeds at low temperatures he con- 
cludes that seeds cease to respire and become completely inert; in 
which case they can sufl'er any degree of reduction in temperature 
without being killed. The killing of the seeds experimented with 
(lobelia) he attri])utes to the fact that the protoplasm had not Itecome 
inert, but simply subdued, and the seeds were thus affected by the low 
temperature. 

As a result of latei- experiments C. De Candolle,^ in keeping some 
seeds under mercury to exclude air, concludes tluit "'seeds can continue 
to subsist in a condition of complete vital inertia, from Avhich they 
recover whenever the conditions of the surrounding medium permits 
their 'energids,' or living masses of their cells, to respire and assim- 
ilate." He compares the protoplasm in latent life to an explosive 
mixture, having the faculty of reviving whenever the conditions are 
favorable. This comparison seems rather an unfortunate one; yet, 
within a certain measure it is probably true. 

"Revue Scientifique, ser. 4, 4: 321-326, 1895. 
&Pop. Sci. Monthly, 51: 106-111, 1897. 



RESPIRATION OF SP:EDS. 79 

It is now ({uito <4eiicralh' iicceptod that respi ration is not absolutely 
necessary for Mic maintenance of seed life, notwithstanding- the fact 
that Gray contended that seeds would die of suifocation if air were 
excluded." The experiments of Gig-lioli''' in keeping seeds of Medlcago 
saflvd immersed in various licpiids for approximately sixteen years, 
after which many responded to germination tests, has done much 
toward demonstrating the fact that seeds can live for a considerable 
time in conditions prohil)iting respiration. 

Kochs'" succeeded in keeping seeds for many months in the vacuum 
of a Geisslor tube without being al)le to detect the presence of any 
carbon dioxid, and consequently he concluded that there was no gas 
given off by intramolecular respiration. 

Romanes'' kept various seeds in vacuum in glass tubes for 15 months 
and the sccmIs were not killed. However, his vitality tests can not be 
considered as entirely satisfactory. In the first place, the number of 
seeds used (ten) Avas too small; secondly, the variations in the results, 
even in the controls, indicate that the samples were not of very good 
quality. 

In the experiments of the writer cabbage and onion seed were kept 
in a \acuum over sulphuric acid for 1S2 days. During this time all of 
the free water had been extracted from the seed. When again con- 
nected with a ^•acuum gauge the dial showed that there was not the 
slightest change in pressure, and that consequently no evolution of 
gases had taken place. The cabbage germinated 75 per cent and the 
onion 73 per c(Mit as compared Avith 81 and 74 per cent, respectively, 
for the controls. 

The results of the various experiments above given demonstrate 
quite fully that the vitality of seeds, as we conuuonly know them, is 
not interfered with if they are ke])t in conditions pi'ohibiting respira- 
tion. Brown and Escombe' hold that all chemical action ceases at 
temperatures of liipiid air. They accordingly conclude that " any 
consideral)le internal chemical changes in the protoplasts are rendered 
impossiljle at temperatures of —ISO-" to — 19U' ' C, and that we must 
consequently regard the protoplasm in resting* seeds as existing in an 
absolutel}' inert state, devoid of any trace of luetabolic activity and 
3'et conserving the potentiality of life * * * And since at such low 
temperatures metabolic activity is inconceivable an immortality of the 
individual protoplasts is conceivable providing that the low tempera- 
tures be maintained." 

«Amer. Jour, of Sci., M series, 24: 297, 1882. 

'^Nature, 52: 544, 1895. 

cBiol. Centrlil., 10: 673-686, 1890. 

f'Proc. Roy. Soc, 54: 335-337, 1893. 

<Ibid., 62: 160-165, 1897-98. 



80 THE VITALITY AND GERMINATION UK SEEDS. 

Giglioli " arrived at practically the .same conclusions when he said: 

It is a c-oiiiiiioii iidtidu that V\iv, or capacity for life, is always cdnnected with con- 
tinuous chemical and ])hysical change * * * The very existence of living matter is 
supposed to imply change. There is now reason for beheving tliat living matter 
may exist, in a completely passive state, without any chemical change whatever, 
and may therefore maintain its special properties for an in<lelinite time, as is the 
case with mineral and all lifeless inatter. Chemical change in living matter means 
active life, the wear and tear of which necessarily leads to death. Latent life, when 
com})letely jiassive in a chemical sense, ought to be life without death. 

But even though ordinary" respiratory exchang'es are not necessary 
for the maintenance of vitality, and (granting that intramoleciiiar 
respiration does not occur in the resting j^rotoplasts, there is no exper- 
imental evidence pointing to the fact that all chemical action ceases, 
although some writers, as has already been shown, maintain the view 
that living matter may exist in a completely passive state. If '"com- 
pletely passive'' meant devoid of respirator}' activities none Avould dare 
dissent; but that seeds are entirely quiescent under any known con- 
ditions has not been proved. To conceive of all activity ceasing 
within the seed under certain conditions, and that with such cessation 
of activity an inunortality of the seed is possible, i. e., if such con- 
ditions continue to exist, is, from our present knowledge of the chem- 
istry and behavior of the living cell, impossible. In Giglioli's experi- 
ments respiration was undoubtedly prevented, and, according to his 
own conclusions, vitality should have been preserved, for he says ''in 
the a])sence of any chemical change the special properties ma}' he main- 
tained indefinitely.'' But, in liis own experiments, the special prop- 
erties were not maintained, for all of the seeds with which he experi- 
mented deteriorated yery nuich, and many died. Granting that those 
which suffered the greatest loss in vitality were injured by the pres- 
ence of the particidar gas or licjuid used there remain no means of 
accounting for the deterioration in those giving the highest percentages 
of germiriation. His experiments were made for the most i)art with 
Medicaijo .sotny/^ which, tinder ordinary conditions of storage, is espe- 
cially long lived. Samek 'Mias shown that seed of JfrtZ/'racjo mtlca 11 
years old was capa))le of germinating 54 per cent. (Jiglioli succeeded 
in getting a germination of only 56.56 per cent after a little more than 
16 years in hydrogen, and 81:.;20 per cent when they had been kept in 
carbon monoxid. Jodin '■ kept peas immersed in mercury for 4^ years 
and they germinated SO per cent. After 10 years the vitality had 
fallen to 44 per cent. Nobbe obtained a germination of 33 per cent 
in peas 10 years old which had been stored under normal conditions. 
Likewise the experiments of Brown and Escombe do not justify the 

« Nature, 52: 544-545, 1895. 

^ Tirol, landw. Bliitter, 13: 161-162, 1894. 

cAmi. Agron., 23: 433-471, 1897. 



KES PI RATION OF SEEDS. 81 

coiicliisioiis which thov hii\c drawn. It is now dctinitoly known that 
all chemical actions do not cease at the temperature of li(jiud air. Thus 
it can not be granted that the protoplasm becomes inert as a result of 
the reduction in temperature. Maquenne" more nearly expressed the 
true cop.ditions applicable to low temperatures when he wrote that 
with dessication, at low temperatures, seeds are transformed from a 
condition of diminished activity -into a state of suspended life. But 
there are still other factors to be considered. The veg-etative functions 
ma}" cease, metabolic processes may ])e at a standstill, intramolecular 
respiration need not exist, 3'et vitality is not, nor ever has been, pre- 
served; sooner or later life becomes extinct. What does this signify? 
The gradual process of devitalization means chemical change, and 
chemical change means activity within the cells. We nuist not forget 
the great complexity of the composition of the protoplasmic bodies 
which go to make up a seed. The chemistry of the living cell is still 
surrounded l>y many difficulties and is likewise tilled with many sur- 
prises, and before the (piestion of the vitalit}- of seeds can be under- 
stood a more comprehensive knowledge of both the functions and 
composition of the cell contents is necessary. 

It is well known tliat all organic compounds are made u}) of a very 
feW' elementary substances, but the numerous and o])scure ways in 
which they are put together furnish questions of the greatest per- 
plexity. kSubstances having the same elements may diU'er widely as 
to their properties. IMoreover, isomeric substances — i. e., those hav- 
ing the same elements in the same proportions, giving an equivalent 
molecular weight — are usually very different in their chemical reac- 
tions and physiological functions. As yet this intramolecular atomic 
rearrangement is but vaguely understood, and the writer ventures to 
suggest that w ith a more comprehensive knowledge of the chemistry 
of the living cell some such chemical activity will be discovered. 
With these discoveries will come, perhaps, an understanding of the 
devitalization of seeds, and with it the theory of the immortalit}^ of 
seeds wdll vanish. 

SUMMARY. 

(1) Seeds, like other living organisms, respire when subjected to 
normal conditions of storage. 

(2) Respiration means a transformation of energy, and consecpiently 
a premature death of the seed. 

(3) W^ithin certain limits respiration is directl}^ proportional to the 
amovuit of w^ater present in the seeds and to the temperature at which 
they are stored. 

(4) B}' decreasing the water content of seeds respiration is reduced 
and vitality greatly prolonged. 

"Conipt. Rend., 134: 1243-1246, 1902. 
25037— No. 58—04 (i 



82 THK VITALITY AND GERMINATION (>K SKP]DS. 

(5) III most seeds tlir ([iiaiitity of oxygen ii])sor))(Ml Mn>;itly exceeds 
the (luaiititv of carbon dioxid evolved. 

(r») llespiration is nearl}" as active in the dark as in the liglit. 

(T) Respiration apparently is not necessar}- for the maintenance of 
seed life. 

(8) A cessation of respiration does not mean a cessation of chemical 
activities. 

ENZYMES IN SEEDS AND THE PART THEY PLAY IN THE 
PRESERVATION OF VITALITY. 

DurincT the past decade the so-called unorganized ferments have 
taken an important place amono- th(> sul)jects of biological research. 
Our knowledge of their wide distribution has increased manj^ fold. 
The part they play in botli ana])olisni and catal)olism has furnished us 
many surprises, but with all of the work that hasljeen done our knowl- 
edge of these most complex compounds is very limited. 

The part that enz3'mes pla}' in the processes of germination is of the 
utmost importance. It is now quite well understood that they are 
developed as germination progresses. They act on the most complex 
reserve food products, converting them into simpler substances that 
can be more readily utilized by the growing seedling. 

However, even in this connection there is a great diversity of opinion, 
especially as to their distribution and enzymic action within the endo- 
sperm itself. Puriewitsch," (Jri'iss,''' and Ilansteen'' are cited by Brown 
and Escom])e"' as holding the view that the amyliferous cells of the 
endosperm of the grasses can digest their reserve materials independ- 
entl}^ of any action of the embryo — i. e., the starch-bearing cells are 
living cells and secrete enzymes in the grasses as well as in the coty- 
ledonous cells of Liqy/nuK^ l^JiaseohiK, and R/clnus. In 1890, Brown 
and Mori'is'' did not find such to be the case; but the results of Purie- 
witsch, (Iruss, and Hanstecn led to a duplication of the experiments 
by Brown and Escoml)e in 1S98. At this time they demonstrated that 
the amylif(>rous cells play no part in the chemical changes which take 
place during the process of germination, l)ut on the contrary that the 
enzymic action in the endosperm of the grasses is confined to the 
aleuron laj'er. 

But the purpose of the present paper is not to consider the localiza- 
tion, of the particular enzyme, and nuich less the action of enzymes 
during germination. At this time quite another question is to be 

«Pringsheinis Jahrlj., 31: 1, 1897. 

^'Laiidw. Jahrbiicher, 189(i, p. 385. 

'■Flora, 79: 419, 1894. 

f^Proc. Roy. Soc, 63: .3-L'5, 1898. 

<■ Jour. Clieiii. Soc, London, 57: 408-528, 1890. 



ENZYMKS IN SKEDS. 83 

coiisidcriHl, \'i/., Ill w liiit way do riizyiucs rimclioii in tlic, i)r('S('rvatioii 
of vitality '. 

i\Ia({iionnc " points to the view that the vitality of seeds is dependent 
on the .sta})ility of the })aitieular fm-iiUMit present. Pie attributes the 
l)rolon<^atiouof vitality in seeds that are kept dry to the l)etter pi'eser- 
vatioii of the enzymes. This \iew has ])een laru-eiy strengthened as a, 
result of the investigations made by Thompson/^ Waugli,'' Sharpe,'' and 
others, in which they have shown that the artiticial use of enzymes 
may grcatl}' increase the percentage of germination in some old s(mkIs. 
By the use of diastase the percentage of germination of 12-year-okl 
tomato seed lias l)een increased more than GOO per cent. 

If the suggestions made by Ma([uenne were true in every sense, then 
dead seeds should be awakened into activity by artiiicially supplying 
the necessary enzymes; ])ut this can not be, or never has been, accom- 
plished. True, many experiments have Ix^en recorded in which a 
greater percentage of seed has been induced to germinate by the judi- 
cious use of conunercial enzymes than ])y the ordinary methods of 
germination; l)ut this treatment is applicalde only where the vital 
energy is simply at a low el)l) and does not in any way ati'ect dead 
seeds. The experiments of the Avriter with naked radicles from the 
embryos of living and dead beans have shown the presence of enz3^mes 
in both. The carefully excised radicles were ground and macerated 
in water for one hour. The filtrate was then added to dilute solutions 
of starch paste. The solutions from the living eml)ryos gave rise to 
an energetic h3'drolytic action. In all cases hydrolysis was sufhciently 
advanced to give a clear reaction with Fehling's solution. The solu- 
tions extracted from the radicles from the dead beans also gave reac- 
tions sufficiently clear to indicate that there was still some ferment 
present.'' 

However, the hydrolysis was scarcely more than l)egun, gi\ ing only 
a ])rown color with iodin, Init not reacting with Fehling's solution. 
Results of a similar character were obtained from portions of t\w, seed 

f'Anu. Agron. 26: 321-332, 1900; Compt. Kciid., 134: ]243-124(), 1902. 

& Gartenflora, 45: 344, 1896. 

'•Ann. Report, Vt. Agr. Exj). Stu., l.S9()-97, and Science, N. S., 6: 950-952, 1S97. 

''Thirteenth Annual Report, Masn. Hatch Exp. Sta., Jan., 1901, pp. 74-83. 

' This wan a sample of "Valentine" beans grown in 1897. The same year tiiey 
tested 97.3 per cent. In March, 1898, the same sample tested 87 i)er cent. At tliis 
time they were sent to Orlando, Fla., where tliey remained until May 8, 1899, 
aj)proximately fourteen months. The l)eans were then returned and numerous 
germination tests were made at irregular intervals, l)ut in no I'ase was there any indi- 
cation of vitality. Several samples were also treated with "Taka" diastase (solu- 
tions varying in strength from 2 to 10 ])er cent), hut none was stimulated into 
gei-mination. The radicles were tested for enzymes iu tlie spring of 1902, nearly 
three years after the beans lirst failetl to germinate, at which time they were nearlj' 
6 years old. 



84 THE VITALITY AND GERMINATION OF SEEDS. 

taken from the point of union of the axis and the cotyledons. These 
possessed stronger hydrolytic powers, the preparations from tlie living- 
and dead l)eans each giving clear reactions with Fehling's solution. 
A third series of tests was made by stopping the germination of l)eans 
when the radicles were from 1 to 1.5 cm. long. These were then kept 
quite dry for nearly seven months, after which the dessicated radicles 
were liroken oli" and macerated like the above. This solution was then 
allowed to act on starch paste, and the tratisformations wer(^ almost as 
rapid and complete as when a 1 per cent solution of commercial ''Taka" 
diastase was used. 

These results lead one to believe that the loss of vitality in seeds is 
not due to tlie disorganization of the enzymes present. There is some- 
thing more fundamental and probably more complex to whicli we must 
look for this life-giving pi'inciple. True, as Ma<[uenne has suggested, 
there is a close relationship between the loss of \'itality in seeds and 
the decom])osition of enzymes. 

In ordei' to determine what such a relationship might signify, the 
following series of experiments were made: 

Beans, peas, cabbage, lettuce, onion, ])]dox, and pans}^ seed, with 
definite quantities of good commercial "" Taka" diastase, were put up 
in bottles of 120 cc. capacity, as folloAVs: 

(1) In bottle closed with cork stopper. 

(2) In bottle closed w'ith cork stopper and paraffined. 

(8) 0.5 cc. of water in the bottle with the seeds and the diastase, the 
bottle sealed Avith paraffin. 

(4) 1 cc. of water in the bottle with the seeds and the diastase, the 
bottle sealed with paraffin. 

(5) 2 cc. of water in the bottle with the seeds and the diastase, the 
l)ottle sealed with paraffin. 

(6) 3 cc. of water in the bottle with the seeds and the diastase, the 
bottle sealed with paraffin. 

(7) 4 cc. of water in the bottle with the seeds and the diastase, the 
bottle sealed with paraffin. 

The water in each case was carefully added on small strips of tilter 
paper and never were the seeds or the diastase wet, only becoming 
gradually moist as the water was absorbed. 

These different preparations, each containing one of each of the sam- 
ples of seeds and a definite ({uantity of the dr^^ powdered diastase, 
were then maintained at the temperature of the laboratory for a period 
of 85 daj^s. At the end of that time the vitality of the seeds was deter- 
mined and simultaneously the hydrolytic power of the diastase was 
ascertained. The results of the germination tests are given in Table 
XXIX. The effect of the increased quantity of moisture on the diastase 
is given in the discussion following the table. 



ENZYMES IN SEEDR. 



85 



Table XXIX.— /.on 



III ritaliti/ of sif(Js ifilli viirijhK] (h't/re('.'< of inuistnrr ivIk'h kcjit (it 
ord'nuini room icmjicrature. 

[Duration of experiment. So days.] 



Labor- 


PreparatioH 
of siiniiilc. 


Amount 
of water 
added. 






Percentage of germination. 




iitory 
niim- 
l»"r. 


Beans. 


Peas. 


Cabbage. 


Onion. 


Plilox. 


Pansy. 


Average 

of all 
samples. 




('(intnil" ... 


cr. 
None... 


<.»i;. 1) 


90. 


91 . 5 


9.'). 


41.25 


ICi. 


70. G 


1547 


<\,Ykr,\ 


None... 


9.H.0 


or,. 


. 91.0 


92. 5 


52. 


32. 


70. 9 


1548 


rarallUH'd .. 


None... 


9<;.o 


92. 


91.5 


9:5.0 


39. 5 


31.0 


73. 8 


1549 


do 


0.5 


w;. 


92. 


89.0 


88. 8 


28. 5 


2.'). 5 


09.9 


1550 


do 


1.0 


yf>. 


.SS. 


89.0 


C)4.0 


12. 5 


18.0 


01.2 


1551 


do 


•J.O 


9(;.o 


.SC). 


78. 


13.0 


. 5 


2.5 


40. 


1552 


do 


8.0 


94.0 


94.0 


65. 


2.5 


.5 


.5 


40. 1 


1553 


do 


4.0 


90.0 


81.6 


54. 5 


.0 


.0 


.0 


37.0 



"The samples prei>areil. exeepting the control, were in bottles of 120 ee. eai)aeity. 

The above table shows that there was a gradual deterioration in 
vitality as the (juantit}" of water was increased. All stages of injiiiy 
were manifested, ])ut it is not necessary to enter into a discussion of 
the table at this time, inasmuch as similar tal)ulations, showiiij^" the 
injurious etiects of vaiying" quantities of moisure on the seeds, have 
already ])een given on page 38. This table is inserted here in order 
that a comparison can be made with the decomposition of the com- 
mercial diastase used and the loss in vitality of the seeds. 

For a determination of the diastasic activity various quantities of 1 
per cent " Taka" diastase solutions were allowed to act on definite quan- 
tities of a 1 per cent solution of starch paste, the whole being maintained 
at a temperature of from W^ to 48^ C. Ten cubic centimeters of the 
starch solution were taken for each determination, and the amount of 
the diastase solution varied from one-half to 1, 2, 3, and 5 cc. In the 
control sample, consisting of diastase from the original bottle as it was 
kept in the laboratory, 2 cc. of the 1 per cent solution were sufficient to 
cause a complete hydrohsis of the 10 cc. of 1 per cent starch solution. 
In Nos. 1547, 1518, and 1519 the samples from the control bottle, the 
paraffined bottle, and the ])araffined bottle containing 0.5 cc. of water, 
respectively, 3 cc. of the diastase solution were necessary for a com- 
plete hydrolysis. In Nos. 1550, 1551, and 1552 — that is, the samples 
from the ])ottles which contained 1, 2, and 3 cc. of water, respectively — 
the diastase was very much injured as a result of the increased quan- 
tity of watei" in the bottle and 5 cc. of the diastase solution were 
requii-ed to hydrolyze the 10 cc. of the 1 per cent starch paste. No. 
1553 — the sample from the bottle which contained the 1 cc. of water — 
showed that the diastase had been almost completel}" disorganized, 
inasmuch as the greatest quantity used (5 cc. of the 1 per cent diastase 
.solution) was only sufficient to cause a slight hydrolytic action. When 



86 THE VITALITY AND GERMINATION OF SEEDS. 

tested with iodine there was still a deep, ])urplisli-l)liie color. In this 
last case the average percentage of gerniination had decreased to 37.6 
per cent, as compared with 7«).() per cent for the control samples. 
Moreover, in the latter case, the onion, phlox, and pansy seeds were 
killed. 

These results show that there is a remarkable uniformity between 
the loss in vital it}" of seeds and the loss in the enzymic action of the 
"Taka" diastase under similar conditions, but it does not furnish con- 
clusive evidence that the loss in vitality of the seeds is in an}' way 
governed by the particular enzymes present. In fact, the evidence at 
hand better sul)stantiates the opposite view. In the first place dead 
seeds may still contain active ferments. Secondly, the prolonged sub- 
jection of seeds to the action of ether and chloroform is generally 
accompanied by a premature death, and if the seeds are moist the loss 
in vitality is uuich more marked. On the other hand, it is generally 
accepted that either of these gases exerts no injurious effect on the 
hydrolytic action of the various ferments. Townsend " has shown that 
the action of diastase on starch paste is even moi'e energetic in the 
presence than in the absence of ether, but in germination ether usually 
has a retarding influence. In some cases, however, growth is stimu- 
lated ])y the use of ether. 

In the third place enzymes can not l)e the chief factors controlling 
the vitality of a seed, because the more sensitive growing point of 
the radicl(> suffers injur}' much in advance of the other portions of 
the seed. Not inf recpiently in making germination tests do we ffnd 
that the growing tip of the eml)ryo is dead, while other portions of 
the seed may still be living and capable of carrying on all normal met- 
abolic process(>s. The bean is one of the l)est examples for demon- 
strating this fact. Here the radicle may be entirely dead, yet the 
cotyledons may still l)c able to make some growth; but in all seeds 
where the growing tip is dead the remaining portion of the radicle 
may be li^'ing, in which case adventitious roots may l)e formed and 
growth may continue for a considerable time, though very rarely will 
a healthy seedling l)e developed. It thus seems quite clear that the real 
vital elements arc closely associated with the growing point, and when 
this portion of the embryo is once dead the vital energy in the other 
parts of the seed is not of such a nature as to enable growth to con- 
tinue for any length of time. Even though the reserve food products 
are digested they can not be assimilated by the growing radicle, which 
should be the case were enzymes the chief elements to which the 
preservation of vitality is attributed. 

Enzymes play an important part in the vitality of seeds, and are 
undoul)tedly necessary for the normal development of a seedling, but 
the points above given show that the life of a seed is not entirely 

"Bot. Gaz., 1S!»V), 27: 4r>8-4()(). 



SUMMARY. 87 

depeiidcnl on tlio, sta])ilitv of the particular fernioiit or fcnnents 
present. There is soniethinu- more remote, possibly of a simpler but 
proba])ly of a more complex composition, to which we nuist attribute 
the awakening- of the meta))olic processes. Reference is not made 
here to the zymogenic substances which (hnelop into the particular 
ferment, for what has ])een said of tht^ latter ap[)lies (Miually w(dl to 
the former. If the zymogens were pei'fectly preserve* 1 the resulting 
ferments would l)e developed normally and germination would continue 
in the usual manner. 

In conclusion, it ma}' well be emphasized that no single element or 
compound can be isolated as the sole source of vitality in seeds. 
There nuist be a coml)inatiou of factors, each of which plays an 
important role in the preservation of vitality. The desti'uction of 
any one of these factors may ui)set the principles go^'erning• the life 
of a seed, and consequently cause a premature death. 

It is quite probable that the nucleus is one of the most important 
organs governing vitalit}', for unless it continues to function no other 
growth can take place. Other pai-ts of the cell, however, may be of 
equal importance. At all events all hope of future gain nuist c(mie 
from more critical studies of the ccdl contents to know their chemical 
composition and possible reactions. A correct solution of these perplex- 
ing ((uestions is nothing less than a determination of the fundamental 
principles of life. What will ]>e the ultimate results no one is prepared 
to sa}'. 

SUMMARY. 

(1) A seed is a living organism, and must be dealt with as such if 
good results are expected when put under favorable conditions for 
germination. 

(2) The first factoi-s determining the vitality of a seed are maturity, 
weather conditions at the time of harvesting, and methods of harvest- 
ing and curing. 

(3) Immature seeds sown soon after gathering usually germinate 
readily, but if stored the}^ soon lose their vitality. On the other hand, 
well-matured seeds, harvested under favorable conditions, are com- 
parativel}^ long lived when properl}^ handled. 

(4) Seed harvested in damp, rainy weather is much weaker in vital- 
ity than seed harvested under more favoral)le conditions. Likewise, 
seed once injured will never regain its full vigor. 

(5) The curing of the various seeds is of the utmost importance, and 
great care should be taken to prevent excessive heating, otherwise the 
vitality will be greatly lowered. 

(6) The life period of any species of seed, granting that it has beei; 
thoroughly matured and properly harvested and cured, is largely 
dependent on environment. 



88 THE VITALITY AXD GERMINATION OF SEEDS. 

(7) The average life of seeds, as of plants, varies greatly with diti'er- 
ent families, genera, or species, hut there is no relation between the 
longevity of plants and the via})le period of the seeds they bear. The 
seeds of some plants lose their vitality in a few^ weeks or months, 
while others remain viable for a number of years. 

(8) With special precautions and treatment there is no question that 
the^life of seeds may be gi-eatly prolonged beyond that ^\hich a\'(^ know 
at present, though never for centuries, as is frequently stated. Ceases 
so reported can not l)e taken as evidence of the longevity of seeds. 

(9) It is known that seeds retain their vitality much lietter in some 
sections of the country than in others. Tlie part which climatic influ- 
ences pla}^ in the vitality of seeds is of much more importance than is 
generally supposed. 

(10) Experiments have shown that mohture is the chief factor in 
determining the longevity of seeds as they are commercially handled. 
Seeds stored in dry climates retain their vitality much ])etter than 
when stored in places having a humid atmosphere. 

(11) The deleterious action of moisture is greatl}^ augmented if the 
temperature be increased. Not infrequently is vitality destroyed 
within a few weeks or months when tlie seeds are stored in warm, 
moist climates. If stored in a dry climate, the question of temper- 
ature within the normal range is of little moment. 

(12) The storage room for seeds as they are ordinarily handled 
should alwa3^s be dry. If seeds could be kept dry and at tlie same 
time cool, the conditions would l)e almost ideal for the preservation 
of vitality; but the difficulties to be overcome in order to secure a dry 
and cool storage room render this method impracticable. 

(13) The most feasible method for keeping seeds dry and thus insur- 
ing strong vitalit}" is to store them in well ventilated rooms kept dry 
by artificial heat. This method of treatment requires that the seeds 
be well cured and well dried before storing. 

(14) If seeds are not well dried vitality is ])est preserved at tempera- 
tures just above freezing^ provided that the temperature is maintained 
uniformly. 

(15) In no case must the temperature of the storage house be 
increased unless the seed is amply ventilated so that the moisture lib- 
erated from the seed can l)e carried off readily by the currents of warm 
air. If this precaution is not taken the increased humidity of the air 
confined between the seeds will cause a marked injury. For this same 
reason seeds kept at low temperatures during the winter will deterior- 
ate in the warm weather of spring, especially if they contain much 
moisture. 

(16) Most seeds, if flrst carefully dried, can withstand long expos- 
ures to a temperature of 37" C. (98.6 ' F.) without injury, but long 
exposures to a temperature of from 39 ' to -10' C. (102.2 to lo-l F.) 



SUMMARY. 89 

will cause premature death. It' the seeds are kept in a moist atmos- 
}>iiere a temperature of even 30" C. (80 F.) will soon cause a marked 
injury. 

(IT) Seeds can endure any degree of drying without injury; that is, 
))y drying- in a vacuum ovor sulphuric, acid. It is believed that such 
a reduction in the water content is necessary it" \itality is to be pre- 
served for a long jieriod of years. However, with such treatment the 
seed coats become wvy Hnn, and there usually follows a retardation 
in germination as a result of the inal)ility of the seeds to absorb water 
ra|)i(lly enough to bi'ing about the necessary physical and chemical 
transformations for the earlier stages of germination. 

(IS) Seeds that are to )>e sent to counti'ies having moist climates 
should he put up in air-tight packages. E\])eriments have shown 
that by the judicious us(> of l)ottles and paratlined ])ackages seeds can 
be preserved jiractically as well in one climate as in another. 

(ID) It is of th(^ utmost importance that tlu^ sei^ds be dry before 
})eing sealed in bottles or paraffined packages. A drying of ten days 
at a temperature of fi'om 30" to 35' C. (80' to 95 F.) will usually be 
sufficient. ITowev(>r, a l)etter method to follow is to dry until no 
more moisture is given off at a temperature equi\ alent to the maxi- 
mum of the region in which the seeds are to bo distributed. If this 
is not done, the subsecpient increase in temperature will li])erate an 
additional quantity of moisture, which ]>eing confined in the package 
will leave the seeds in a humid atmosphere and a rapid deterioration 
in vitality will follow. 

(20) Expei'iments in storing seeds in open and sealed ])ottles and in 
packages with definite (piantities of moisture and at various known 
temperatures have shown a very close relationship between the loss in 
vitality and the increase in water content, the deterioration likewise 
increasing with the t(Mnperature. 

{'■21) Of a series of experiments the average loss in vitality of seeds 
kept in envelopes in a "dry room" was 21.1!> i)er cent, "trade condi- 
tions" 30.03 per cent, " basement" -12.28 p(M- cent, whih^ the loss in 
the case of seeds stored in bottles was only 8.08, 3.92, and 4.51 per 
cent, respectively. (Sec Table XXV.) 

(22) Seeds under ordinary conditions of storage respire rpiite freely, 
and respiration is much more rapid if nuich moisture is present. 
Within certain limits respiration is directly proportional to the amount 
of moisture present in the seed and inversely proportional to the 
duration of vitality. 

(23) Respiration is not necessar}^ to the life of seeds, as they can he 
kept in conditions unfavorable for respiratory activity and still retain 
their vitality even better than under normal conditions of storage. 
Even though respiration be entirely prevented seeds will continue to 
deteriorate, and sooner or later lose their vitality. 



90 THE VITALITY AND GERMINATION OF SEEDS. 

(24) The continued deterioration in tlio vitality of a seed after res- 
piration has ceased indicates a chemical activit}" within the cells, g-iving 
rise to a transfoi-niation of energy which sooner or later leads to the 
death of the seed. 

(25) Respiration is almost as active in the dark as in the light, pro- 
vided that the temperature and humidity remain the same. 

(26) Ferments and seeds lose all power of activity under similar 
conditions of moisture, and the former are undoubtedly of the utmost 
importance in metabolic activit}", but the evidence at hand goes to 
show that the life of a seed is not dependent on the preservation of 
the particular ferment involved or on the zymogenic substances giving 
rise to the enzyme. 

(27) The life of a seed is undoubtedly dependent on man}- factors, 
but the one important factor governing the longevit}^ of good seed is 
dry7i€ss. 



LITERATURE CITED. 

Bonnier, G., et Mangin, Louis. La fonction respiratoire cliez les veg6taux. Ann. 
sc. nat. bot., s6r. 7, 2: 365-380, 1885. 

Bornemann, G. Versuche iiber Erhaltung der Keimfjihigkeit bei importirten Ramen 
von Wasserpflanzen wiihrcnd des Transportes. Gai-tenflora, 35: 532-534, 1886. 
Also abstract in Bot. Jahresber., Jahrg. XIV, Abt. I, p. 132, 1886. 

Brown, Horace T., and Escomhe, F. Note on the intinence of very low tempera- 
tures on the gernnnative power of seeds. Proc. Roy. Soe. London, 62: 160-165, 
1897-98. 

On the depletion of the endosperm of Ilordeum niJ(j(trc during germination. 

Proc. Roy. Soc. London, 63: 3-25, 1898. 

and Morris, M. Germination of some of tlie Grawinciv. Jour. Clit^m. Soc. 



London, 57: 458-528, 1890. 
Dammek, U. Verpackung und Versandt von Samen, welche ihre Keimkraft schnell 

verlieren. Zeitschr. f. trop. Landw., Bd. 1, No. 2, 1897. Abstract in Bot. 

Centralbl., 70: 190-197, 1897. 
De Candolle, Aug. Pyr. Physiologic v^getale (Conservation des graines), v. 2, p. 

618, Paris, 1832. 
De Candolle, C. Sur la vie latente des graines. Arch, des sci. phys. et nat., ser. 4, 

33: 497-512, 1895. Abstract in Amer. Gard., 18: 339, 1897. 

La vie latente des graines. Revue scientiilque, ser. 4, 4: 321-326, 1895. 

The latent vitality of seeds. Pop. Sci. Monthly, 51: 106-111, 1897. 

et PicTET, R. Recherches concernant Paction des basses tempt'ratures sur la 

faculty germinative des graines. Arch, des sci. phys. et nat., s6r. 3, 2: 629-632, 

1879. Abstract in Just's Botan. Jahresber., Jahrg. VII, Abt. 1, p. 253, 1879. 
Action d'un grand froid prolong^ sur des graines. Arch, des sci. phys. et 



nat., ser. 3, 11: 325-327, 1884. Al)stract in Just's Bot. Jahresber., Jahrg. XII, 

Abt. 1, p. 26, 1884. 
Detmer, W. Vergleicliende Physiologic des Keimungsprocesses der Samen, Jena, 

1880. 
Dew AR and McKendrick. On liquid air. Proc. Roy. Inst., 12: 699, 1892. 
Dixon, H. H. Vitality of seeds. Nature, 64: 256-257, 1901. 



LITERATURE CITED. 91 

Dixox, II. II. On tlio germination of ^:('e(ls after exposure to iiii^li temperatures. 

Notes from the Botanical Scliool of Trinity Colle<>;e, Dublin, [i]!. 17()-18t), 

August, 190!i. 
Edwards et Colin. De 1' influence <le la temperatui'e snr la germination. Ann. den 

sci. nat. l)ot., ser. 2, 1: 257-270,1834. 
(Jn;i,ioi,i, li'AMo. Sulla resistenza di alcuni semi all' azione ])rolungata <li agenti 

chimici gassosi e licjuid. Annuario della li. 8cuola Sn])erior(^ d'Agricoltnra in 

Portici, V. 2, 1880, Napoli, 1881, ^^\ j.. Abstract in Nature, 25: ;{28, 1882. 

Latent, vitality in seeds. Nature, 52: 544-545, 1895. 

(iuAV, A. Latent vitality of seeds. Amer. Jour. Sci., od ser., 24: 297, 1882. 
GutJss, J. Beitragezur Physiologieder Keimung. Landvv. Jahrbiicher, p. 1585, 1890. 
Haiserlandt, F. Ueber die mitere Grenze der Keiunmgstemperature der Samen 

unserer Getreidepfianzen. Pllanzenbaii 1, pjt. 109-117, 1875. Abstract in Bot. 

.Tahresber., p. 777, 1875. 
PIansteex, B. Ueber die Ursachen der Entleerung der Reservestoffe aus Samen. 

Flora, 79: 419, 1894. 
IsiDORE-PiERKE, J. Ueber den Einfiuss der Wiirme und des Beizens mit Kalk und 

Kupfervitriol anf die Keimfiihigkeit des Weizens. Ann. Agron., 2: 177-18], 

1S7(). Abstract in Bot. Jahresber., 4, Abt. 2, p. 880, 1876. 
JoniN, Victor. Recherches snr la germination. Ann. Agron., 23: 43?)-471, 1897. 
8ur le resistance des graines aux temperatures elevees. Compt. Rend., 129: 

893-894, 1899. 
et Gantier, a. La vie latente des graines. Compt. Rend., 122: 1349-1352, 



1896. 

JisT, L. Ueber die Wirkung hoherer Temperaturen auf die Keimfiihigkeit der 
Samen von Trifolium j>ratense. Bot. Zeit., 33 Jahrg. , ji. 52, 1875. 

Lleber die Einwirknng hoherer Temperaturen auf die Erhaltung der Keim- 
fiihigkeit der Samen. Cohn's Beitriige zur Biol, der Pflanzen, 2: 311-348, 1877. 

Kociis, W. Kami die Kontinnitiit der Lebensvorgilnge zeitweilig vollig unterbrochen 
werden? Biol. Centralbl., 10: ()73-686, 1890. 

Koi.KwiTZ, R. Uel)er die Athmung ruhenden Samen. Ber.d.deut.bot. Ges., 19: 
285-287, 1901. 

Krasau, F. "Welche Wiirmegrade kann der Weizensame ertragen, ohne die Keim- 
fiihigkeit zu verlieren? Sitznngsber. d. Wiener Akad.d. Wiss., Abt. L, 48: 195- 
208, 1873. 

Maquenne, L. Snr I'liygrometricite des graines. Compt. Rend., 129: 773-775, 
1899. 

— Recherches sur la germination. Ann. agron., 26: 321-332, 1900. 

Contributions a I'etude de la vie ralentie chez les graines. Compt. Rend., 

134: 1243-1246, 1902. 

Pic'TET, R. De I'emploi methodique des basses temperatures en biologie. Arch, sci 
phys. et nat., Geneve, 30: 293-314, 1893. 

PiETERS, A. J., and Brown, E. Kentucky Bluegrass seed — harvesting, curing, and 
cleaning. Bui. 19, Bureau of Plant Industry, U. S. Dept. of Agriculture, 1902. 

Romanes, C. J. Experiments in germination. Proc. Roy. Soc, 54: 335-337, 1893. 

Sachs, Julius. Beschiidigung und Ti'idtung durch zu hohe Temperatur. Handbuch 
d. exp. Phys. d. Pflanzen, Leipzig, 1865, p. 63. 

Sameic, J. Duration of the vitalitj' of some agricultural see<ls. Tirol, landw. Bliitter, 
13: 161-162, 1894. Al)stract in Exp. Sta. Rec, 6: 429, 1894-95. 

ScHMiD, B. Ueber die Einwirknng von Chlorofonndiimj)fen auf ruhende Samen. 
Ber. d. dent. bot. Ges., 19: 71-76, 1901. 

Selhv, a. D. Germination of the seeds of some common cultivated plants after pro- 
longed immersion in liquid air. Bui. Torr. Bot. Club, 28: 675-679, 1901. 

SiiARPE, PI H. Influence of chemical solutions upon tlu> germination of seeds. 
Thirteenth Annual Report, Mass. Hatch Agr. P^xp. Sta., pp. 74-83, 1901. 



92 THE VITALITY AND GERMINATION OF SEEDS. 

Thiselton-Dyer, Wm. T. Influence of the temperature of liquid hydrogen on the 

germinative power of seeds. Proc. Roy. Soc, 65: 361-368, 1899. 
Thompson, A. Zum Verhalten alter Samen gegen Fermentlosungen. Ciartenflora, 

Jahrg. 45, p. 344, 1896. 
TowNSEND, C. O. The effect of ether upon the germination of seeds and spores. Bot. 

Gaz., 27: 458-466, 1899. 
Tkeviranus, Ludolph C. Physiologie der Gewilchse. Vol.11, p. 578, section 637, 

•1838. [Vitality of seeds as affected by age, heat, and moisture.] 
Uloth, W. Ue]>er die Keimung von Pflanzensamen in Eis. Flora, n. s., Jahrg. 33, 

pp. 266-268, 1875. 
Van Tieghem et Bonnier, G. Recherches sur la vie latente des graines. Bui. Soc. 

Bot. France, 29: 25-29, 149-153, 1882. 
Wartmann, E. L' influence de froids excessifs sur les graines. Arch, des sci. phys. 

etnat., Geneve, 8: 277-279, 1860. 
Recherches sur la v^g^tation (section 3— Role de froids excessifs). Arch, des 

sci. phys. etnat., Geneve, ser. 3, 5: 340-344, 1881. 
Waugh, Frank A. The enzymic ferments hi plant physiology. Science, n. s., 6: 

950-952, 1897. Also Tenth Annual Report Vermont Agr. Exp. Sta., 1896-97. 



INDEX. 

rage. 

Agriculture, Department, Seed Laboratory, relation t( > present work 10 

Alaliama, Auburn, seed-storinor ejxperiment 49 

Alliinii rcjxt, Heleetion for exi)eriinent 10 

Aniyliferous eells, relation to <,a'rnunation of seedjs, note 82 

Angnria citndhis, Helection for experiment 10 

Ann Arbor, Mich. , seed-storing experiment 50 

testing experiment 14-22 

Aplnccv, Daucns carota, selection for experiment 10 

Apparatus for tests of effect of moisture on vitality of seed 30, 31 

seed testing, description and use 11-12 

AMeracesc, Lactuca satira, selection for experiment 10 

Auburn, Ala., place for seed-testing experiments 14-22 

Baton Rouge, La., comparison with Ann Arbor and Mobile for seed storing .. 21-22 

seed-storing experiment 49 

testing experiments 14-22 

Bean seed, ice-house storage, effect 28 

selection for experiment - - 10 

Beans, germination tests, n-sults for various st()rage cimditions 51, 63-65 

seed, respiration ex2)eriment, results 76 

' ' Valentine, ' ' tests 83 

Bluegrass, Kentucky, Poti ]>r<ilt')i><ix, heating in curing, effect on seed 43 

Bonnier and Mangin, plant respiration, conclusion 74 

Van Tieglu'm, tests of respiration of seeds, results 75 

Bmssinici're, Brasi^ira. olcrdcrd and Jxaplmuus sativus, selection for experiment.. 10 

Brown and Escombe, seed germination experiment 80 

views as to chemical action at liquid-air tinnperature ... 79 

Brown and IMorris, and Escomlx', experiments as to enzymes in germination. 82 

Cabbage, germination tests, results for various storage conditions 53, 63-65 

seed, comparison of storage in three climates 21-22 

ice-house storage, effect 28 

moisture and temperature tests of vitaiit}' 36 

respiration exj)eriment, results 76 

vitality in different packages in varying storage 71-74 

selection for experiment ^__ 10 

Carbon dioxid, result of respiration of beans, etc 76, 77, 78 

Carrot seed, germination tests, results for various storage conditions ... ... 55, 63-65 

respiration experiments, results 77 

selection for experiment 10 

Cauliflower seeds, keeping in moist climate, note 13 

( 'harcoal, moss, etc. , sliipping seed in packing 47 

Cliemical activity, relation to latent life 80 

Clement, suggestion for storage of seed 45 

Climates, different, causes of loss of vitality in seeds, discussion 22-24 

Climatic conditions, effect on vitality of seeds, discussion ^ 13-22 

Corn, sweet, germination tests, results for various storage conditions... 56-57,63-65 

selection for experiment 10 

Coville, Frederick V., preface on purpose and scope of jiresent study 5 

< 'Kciifhildce.T, An(/>iri(t ritrullus, selection for experiment - 10 

Curing and drying of seeds, necessity for thoroughness 45 

of seed, importance 87 

De CandoUe, Aug. Pyr., remarks on conservation of seeds 44 

suggestion regarding vitalitj' of seeds 75 

C. , views on respiration of seeds 78 

Diastase, iise in experiments on vitality of seeds 85 

Dry atmosphere in open bottles, effect on vitality of seeds 34 

sealetl 1 )ottles, effect on vitality of seed 34 

heat, effect on vitality of seed, note 31 

Drying and curing of seeds, necessity of thoroughness » 45 

93 



94 INDEX. 

Page. 

Dryness, most iiuportant factor in prolonged vitality of seed 90 

relation to preservation of vitality of seed 87, 88, 89, 90 

Endosperm of grasses, relation to germination, notes 82 

Enzymes in seeds, part in preserving vitality 82-87 

Escombe and Brown, experiments as to enzymes in germination 82 

seed-germination experiment _ 80 

views as to chemical action at liquid-air temperature. . . 79 

Fabace.v, Pisum sativum and Phaseolus vulgaris, selection for experiment 10 

Fazy-Pasteur, suggestion for storage of seed 45 

Ferments, relation to vitality of seeds 90 

unorganized, relation to vitality of seeds 82-87 

Ferry Botanical Fellowship, seed study, relation to present work 10 

Ferry, D. M. , & Co. , seed for experiments 10,15 

Florida, Lake City, seed-storing experiment 49 

testing experiment 14-22 

Gardener, market, value of good seed 46-47 

(jardeners, comjylaints of seeds, n(jte 13 

"Geneva tester" for germination of seeds, modifications and use 11-12 

Germination and vitality of seeds, conclusion from present study 87-90 

of seeds at low temperatures 20-27 

in ice house, effect of ])ackage 27, 28 

various seeds, percentage under differing storage 63-(35 

part of enzymes 82 

tests and apparatus, discussion 1 1-13 

results 50-65 

Germinator, seed testing, method of use 12 

Giglioli, c( )nclusion as to chemical activity in latent life 80 

experiments with seed of Mediaujo sativa 79 

remarks on vitality of seeds 45 

Grasses, endosperm, relation to germination 82 

Gray, contention as to suffocation of seeds 79 

Qriiss, citation as to grass endosperm 82 

Gulf of Mexico, effect of moisture on seeds 13 

Hansteen, citation as to grass endosperm 82 

Harvesting, relation to vitality of seeds 87 

Heating, excessive, danger in curing seed 87 

Hygroscope, crude, improvisation from awns in seed testing 31 

Hydrolysis, presence in experiments on enzymes in seeds, notes 83, 84, 85, 86 

Ice, packing of seeds, effect on vitality, remarks 26-29 

Incubator, seed, test for effect of moisture on vitality 29 

Indian Territory, Wagoner, i)lace for seed-testing experiments 14-22 

seed-storing experiment 50 

Jodin, seed-germi nation experiment, note ,. - 80 

statement as to respiration of seeds 75 

Keejiing seeds, discussion {see also Storage ) 65-74 

Kochs, seed-respiration experiment 79 

Laciuca sativa, selection for experiment - 10 

Latent life, relation of chemical activity 80 

Lettuce, comparison of storage in three climates -^~?? 

germination tests, results for various storage conditions 58, 63-65 

seed, ice-house storage, effect 28 

loss of vitality in tropical climate, note 25 

moisture and temperature test of vitality 36 

respiration exi)eriment, results 77 

selection for experiment 10 

Liliace.r, Allium cepa, selection for experiment 10 

Longevity of seed, dryness most important factor 90 

Lycopersicdn lucoperskum, selection for experiment 10 

IMaquenne, statement as to seeds in low temperatures, note 81 

suggestion as to res] iirati< )u of seeds 74 

suggestions as to vitality of seeds 83 



INDKX. 95 

I'ago. 

Market i^anU'iicr, vulur of ixodd Hee*!, rciiiurks 4»>-47 

INIatni-ity, relation to vitality <if seeds ^7 

Maiiji'in ami J'MHinier, plant resj)irati(iii, conelusioii 74 

Mi'(Hca(jo ifdlira, seed, experiments of Uijilioli 7!) 

Gi<,di<)liand Saniek 80 

IMiclii^an, Ann Arl)nr, seed-storing experiments f»0 

University, seed study, relation to present work 10 

Mobile, Ala., comijarison with Baton Kou}j;e and Ann Arbor for storing seed.. 21-22 

place for seed-testing experiments lti-22 

seed-storing experiment 49 

Moist atmosphere in sealed bottles, severe injury to seeds 33 

Moisture and temperature, effect upon vitality of seeds, discussion 24-36 

summary of results . . 35 

relation to vitality of seed, tables and comment. . . 38-44 

effect on vitality of seeds at high temperatures, remarks 29 

in tixed temperatures, discussion 36-44 

hindrance in keeping seeds, provision 13 

relation to endurance of heat by seed 25 

longevity of seed 87, 8S, 89, 90 

test of seeds in special packages 66 

Morris and Brown, experiments as to enz\^mes in germination 82 

Moss, cliarcoal, etc. , shipping seed 47 

New Hampshire, Durham, place for seed-testing experiments 14-22 

seed-storing experiment 50 

New Orleans, rapidity of deterioration of seed 47 

Newcomlje, Dr. F. V., direction of present study - 10 

Nol)be, seed germination experiment, note 80 

Oily seed, resistance of low temperatures, note 28 

Onion, germination tests, results for various storage conditions 59, 63-65 

seed, comparison of storage in three climates 21-22 

ice-house storage, effect 28 

moisture and temperature test of vitality 36 

respiration experiments, results 77-78 

vitality in different packages in varjing storagi' 71-74 

selection for experiment 10 

Packages, seed, different kinds for moisture test 66 

relation to i)reservation of vitality of seeds 89 

special, experiments in shipping and keepung seeds 65-74 

Packing seed for shipping ex])eriments 47 

Pansy, germination tests, results for various storage conditions 60, 63-65 

selection for exjteriment 10 

Paratiined ])ackages, vitality of seeds in storage 69-71 

Pea, selecti( m for experiment 10 

Peas, germination at temperature of ire water, remarlcs 27 

tests, results for various storage conditions 52, 63-()5 

seed, moisture ami tem]ierature, test of vitality 36 

JVia.^foliix riih/(iris, selection for study 10 

Phlox, germination tests, results for various storage conditions 60, 63-65 

I'Isiim iidtiruiii, selection for experiment 10 

Planters, complaints of seeds, note 13 

J'od praienfils, heating in curing, effect on seed 43 

Podcew, Zed vuvi/k, selection for experiment, note 10 

Poison, danger from brass and copper in seed testing, notes II, 12 

I'oleinonlacen', Plilox dnmirnondi i , selectif)n for study ■ - 10 

Porto Rico, San Juan, seed storing experiment 48 

testing experiments 14-22 

Precipitation and temperature, relation to vitality of seeds, ])ercentages 23 

effect on vitality of seeds, graphic representation 24 

Protoplasm, changes in respiration of seed 78 

Pr( )toplasts, changes in respiration experiments 79 

Puriewitsch, citation as to grass endosperm 82 

Radish, germination tests, results for various storage conditions 54, 63-65 

selection for experiment 10 

Respiration, necessity to life of seeds, remarks 79 

of seeds, discussion , 74-82 



96 INDEX. 

Page. 

KeHpiriitioii of sei'ils, suinniary of conclusions 81-82 

ivlati( >n to vitality of seeds 89, 90 

Romanes, seed resi)iration exiieriment - 79 

Saniek, seed (jerniination experiment, note 80 

Sharpe, citation as to enzymes 83 

Shipping and keeping of seeds in special packages, discussion 65-74 

storing seeds, method for preservation of vitality 44-65 

seed in charcoal, moss, etc. , remarks 47 

Soaking seeds for germination tests, advantage 12 

,Solannce:v, Lycopersicon bfcopenicum, selection for ex[)eriment 10 

Spalding, Prof. V. M. , direction of present study 10 

Starch in seed, relation to germination in ice-house storage. 28 

Storage (keeping) and shipping of seeds in special packages, discussion 65-74 

room, warehouse, character for seeds, remarks 46 

seed, relation to jireservation of vitality 88, 89 

Storing and shi])ping seeds, methods ior preservation of vitality 44-65 

seeds, relative merits of Mobile, Baton Rouge, and Ann Arljor 21-22 

Temperature and moisture, effect on vitality of seed, discussion 24-36 

summary of results 35 

relation to vitality of seed, tables and comment — 38-44 

]ireeipitation, relation to vitality of seed, percentages 23 

maxinnnn limit of endurance by seed, variation 25 

relation to vitality of seeds _ 87, 88, 89-90 

Temperatures, tixed, effect of definite moist uie on vitality of seed, discussion.. 36-44 

high, vitality of seeds, effect of moisture 29 

Test, germination, first, for climate, results, tattle and connnent 15-J6, 18-21 

second, for climate, results, table and comment 16-17, 18-21 

Tester, Geneva, germination of seeds, modification and use 11-12 

Testing seeds, conditions of experiments 14, 29-31, 36 

Tests, germination, results 50-65 

various vegetable seeds 11 

seed, for effect of moisture on vitality at high temperatures 29 

vitality, importance of nearness to planting time 47 

Thompson, citation as to enzymes 83 

Tomato, germination tests, results for various storage coiulitions (ii, 63-65 

seed, ice-house storage, effect 28 

moisture and temperature test of vitality 36 

selection for experiment 10 

Tropical climate, loss of vitality of lettuce seed 25 

Vacuum, seed respiration experiments 79 

Van Tieghem and Bonnier, tests of respiration of seeds, results 75 

Violaceu', Viola tricolor, selection for exjieriment 10 

Vitality and germination of seeds, conclusions from present study, sunuaury. . 87-90 

caljbage and onion seed, relation to storage and jtackage 71-74 

seed, effect of climatic conditions, discaission 13-22 

definite moisture in fixed temperatures, discussion 36-44 

temperature and moisture, discussion 24-36 

enzymes in preservation j 82-87 

loss for various seeds under different stcjrage conditions 63-65 

in different climates, causes 22-24 

with varying moisture at ordinary temperature 85 

low, worse than dead seed, note 46 

{)reservation by methods of storing and shipping 44-65 

relation of moisture and temperature, tal)les and comment 38-44 

storage in different kinds of jtackages, results 68 

Warehouse, seed, storage, character, remarks 46 

Water content of seeds, increase, effect on vitality 44 

Watermelon, gemination tests, results for various storage conditions 62, 63-65 

seed, ice-house storage, effect 28 

selection for experiment 10 

Waugh, citation as to enzymes 83 

Zea mai/n, selection for experiment, note , 10 

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